Class 10

Punjab State Board PSEB 10th Class Science Important Questions Chapter 1 Chemical Reactions and Equations Important Questions and Answers.

PSEB 10th Class Science Important Questions Chapter 1 Chemical Reactions and Equations

Long Answer Type Questions

Question 1.
How do we write balanced chemical equations?
Answer:
To understand the method to write balanced chemical equation, let us take an example.
Zinc + Sulphuric acid → Zinc sulphate + hydrogen This equation can be written as below
Zn + H₂SO₄ → ZnSO₄ + H₂

Check the number of atoms on both sides of the arrow.

In the equation, number of atoms are same on the both sides of the arrow, thus it is balanced chemical equation.
Now let us try to balance the following chemical equation
Fe + H₂O → Fe₃O₄ + H₂

Step I: Make a list of atoms of different elements in the unbalanced equation

Step II: Choose a compound with maximum number of atoms for balancing whether it is reactant or product. Choose an element with maximum number of atoms in the choosen compound. On this basis we choose Fe₃O₄ and in it we choose the element oxygen. On the right, there are four atoms of oxygen and on the left only one.

To balance, oxygen atom

To equalize the number of atoms, we can not change the formulae of elements and compounds taking part in the reaction e.g. to balance oxygen atoms we can put coefficient ‘4’ and can write 4H20 but we cannot write H204 or (H₂O)₄ or (H₂O₄).

A partially balanced equation will be
Fe + 4H₂O → Fe₃O₄ + H₂
(Partially balanced equation)

Step III: Fe and H are still unbalanced. Choose any one and move ahead. To balance hydrogen atoms, on left side, make number at atoms of hydrogen ‘4’.

Now equation becomes
Fe + 4 H₂O → Fe₃O₄ + 4H₂

Step IV: Check the above equation and choose third element which still is unbalanced. We will find that only iron is the element, which remains to be balanced.

To balance Fe we take 3 atoms of Fe on the left side.
3Fe + 4 H₂O → Fe₃O₄ + 4H₂

Step V: At the end, let us count the number ofatoms of elements on both sides of the equation
3 Fe + 4H₂O → Fe₃O₄ + 4H₂ (Balanced equation)

Number of atoms of every element on both sides of the equation are equal. Therefore this equation is now balanced. This method of balancing chemical equations is known as hit and trial method because we use smallest integral coefficient to balance the equation.

Step VI: To write the symbols for physical states. There is no information given about the physical state in the above balanced equation.
To make chemical equation more informative, write the physical states with the reactants and products. To represent the states of solid, liquid, gas, aqueous of the reactants and products we write (s), (l), (g) and (aq) respectively with them. When reactant or product is present in the form of solution in water then word (aq) is written.

Thus, balanced equation will be
3Fe(s) + 4H₂O (g) → Fe₃O₄(s) + 4H₂(g)
when (g) is used with water, then it means that water is used in the form of steam in the reaction. Usually, physical state is not mentioned in the chemical equation until it is very necessary.

Sometimes the conditions of the reaction like temperature, pressure, catalyst etc. are shown over or under the arrow e.g.

Question 2.
Give types of chemical reactions with examples.
Answer:
The various types of chemical reactions are :
1. Combination reactions: In these reactions two or more than two reactants combine to form a single product. Such reactions are known as combination reactions.

Example: Calcium oxide reacts with water to form calcium hydoxide (slaked lime) and a lot of heat is evolved.

In this reaction calcium oxide and water combine to give single product calcium hydroxide.

2. Dissociation or Decomposition reactions: In these reactions single reactant breaks into two or more than two new substances. Such reactions are called dissociation reactions.

Examples of dissociation reaction :

3. Displacement reactions: When an element displaces another element from a compound, then it is called displacement reaction.

Examples:

4. Double displacement reactions. In such a reaction two different atoms or group of atoms exchange themselves with each other.

Example :

Question 3.
Briefly describe oxidation and reduction with suitable examples.
Answer:
Oxidation. Oxidation of a substance takes place in a reaction when there is gain of oxygen or loss of hydrogen in it and opposite to it reduction takes places when there is loss of oxygen or gain of hydrogen.

Example: A black coating of copper (II) oxide is seen on copper powder. Why this black substance is formed?
This copper oxide is formed due to combination of copper with oxygen.

If on this heated substance hydrogen gas is allowed to flow, this black coloured coating changes into brown colour because in these circumstances reverse reaction takes place and copper is again obtained.

When there is gain of oxygen in a substance in a reaction we say oxidation of the substance has taken place and when there is loss of oxygen we say reduction of the substance has taken place.

There is loss of oxygen in copper (II) oxide, therefore it gets reduced. There is gain of oxygen in hydrogen, therefore it is oxidized. Thus, in a reaction one of the reactant is oxidized and other reactant is reduced. Such type of reactions are called reduction-oxidation reactions or redox reactions.

Other examples of redox reaction are :

• ZnO + C → Zn + CO
• MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂
• In this reaction carbon is oxidized to become CO and ZnO is reduced to Zn.
• In this reaction HCl is oxidized to Cl₂ and MnO₂ is reduced to MnCl₂.

Question 4.
Balance the following chemical equations.
(i) H₂ + N₂ → NH₃
Answer:
3H₂ + N₂ → 2NHg

(ii) BaCl₂ + Al₂(SO₄)₃ → AlCl₃ + BaSO₄
Answer:
3BaCl₂ + Al₂(SO₄)₂ → 2AlCl₃ + 3BaSO₄

(iii) H₂S + O₂ → SO₂ + H₂O
Answer:
2H₂S + 3O₂ → 2SO₂ + 2H₂O

(iv) KBr + BaI₂ → KI +BaBr₂
Answer:
2KBr + BaI₂ → 2KI + BaBr₂

(v) Al + CuCl₂ → AlCl₃ + Cu
Answer:
2Al + 3CuCl₂ → 2AlCl₃ + 3Cu

(vi) AgNOg + Cu → Cu(NO₃)₂ +Ag
Answer:
2AgNOg + Cu → Cu(NO3)2 + 2Ag

(vii) Al (OH)₃ → Al₂O3 + H₂O
Answer:
2Al(OH)₃ → Al₂O₃ + 3H₂O

(viii) NH₃ + CuO → Cu + N₂ + H₂O
Answer:
2NH₃ + 3CuO → Cu + N₂ + 3H₂O

(ix) KClO₃ → KCl + O₂
Answer:
2KClO₃ → 2KCl + 3O₂

(x) BaCl₂ + K₂SO₄ → 2BaSO₄ + KCl
Answer:
BaCl₂ + K₂SO₄ → BaSO₄ + 2KCl.

Short Answer Type Questions

Question 1.
Give two examples from our daily life to show that chemical changes do take place in our daily life.
Answer:

1. Fermentation of grapes take place.
2. Our body digests the food.
3. In summer, if milk is left in the room, we can see a change in it as it becomes sour.

Question 2.
Differentiate between balanced and skeletal chemical equation.
Answer:
Balanced equation. If number of atoms of each element are same before and after the reaction, then such a reaction is balanced chemical reaction.

Skeletal chemical equation. When number of atoms of each element before and after the reaction are not same then such a chemical equation is called skeletal Chemical equation.

Question 3.
What are the necessary requirements while writing a chemical equation?
Answer:
These are :

• It represents a true chemical change.
• It should be balanced.
• It should represent physical states of the reactants and products.
• It should indicate the necessary conditions required for the reaction to occur.
• It should represent heat changes during reactions.

Question 4.
Give one example each of balanced and skeletal equation.
Answer:
2KCl + O₂ → 2 KCl(s) + 3O₂(g)
This is example of balanced equation.
Zn + AgNO₃(aq) → Zn (NO₃)₂ + Ag
This is example of skeletal equation.

Question 5.
Give chemical formula for slaked lime and one use of it.
Answer:
Chemical formula -Ca(OH)₂. Solution of slaked lime is used for white washing the buildings.

Question 6.
Why there is a shine on the walls after two-three days of white washing?
Answer:
Calcium hydroxide reacts slowly with carbon dioxide present in the air and form a thin layer of calcium carbonate on the walls. After 2-3 days of white wash, calcium carbonate is formed due to which there is a shine on the walls.

Question 7.
Give chemical formula of marble and give reaction to show bow it is formed?
Answer:
Marble is also known as calcium carbonate.
Its chemical formula is CaCO₃ Reaction to show its formation

Question 8.
MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂
How oxidation and reduction in the above reaction is taking place? What is the name of such reaction?
Answer:

Such a reaction is called redox reaction.

Question 9.

Complete the above reaction and tell the colour of the product.
Answer:
Above reaction is :

colour of PbO is yellow.

Question 10.
Give colours of following solutions.
1. FeSO₄
Answer:
FeSO₄ → green

2. CuS04
Answer:
CuSO₄ → blue

Question 11.
What is rusting? What is the chemical formula of rust. What is its loss?
Answer:
New articles made up of iron are shiny but after some time a reddish brown coating is seen on their surface. Usually it is called rusting of iron.

Chemical formula of rust – Fe₂O₃.H₂O (Hydrated iron (III) oxide)
It is powdery substance that gets removed from the surface and due to this iron articles are getting damaged.

Question 12.
Fats are oils containing foods, when kept for long time then what change take place in them? What is name of this process?
Answer:
Fats and oils containing foods, when kept for long time, results in the change of their taste and smell. This process is named as rancidity.

Question 13.
How can we stop rancidity?
Answer:

• To slower down the rate of oxidation, antioxidants are added to food items.
• By keeping food items in air tight containers.
• By flushing nitrogen gas in packets of chips so as to stop the oxidation of chips.

Question 14.
Zinc metal can displace copper from copper sulphate solution. But copper metal can not displace zinc from the solution of Zinc sulphate. Give reason.
Answer:
zinc is more reactive than copper. It can displace copper from copper sulphate solution. Copper is less reactive than zinc thus copper can not displace zinc from zinc sulphate solution.

Question 15.
What happens when zinc rod is placed in copper sulphate solution? Give chemical equation for the reaction.
Answer:
zinc is more reactive than copper. It wall displace copper from solution of copper sulphate and zinc sulphate is formed. Blue colour of the solution of copper sulphate change to white slowly.

Question 16.
What is lime mitigation? Why there is sound of shuun-shuun in this process? Give chemical equation representing the reaction.
Answer:
When quick lime is mixed with water, it changes to slaked lime. This is lime mitigation. This is a exothermic reaction and heat is evolved due to which there is sound of shuun-shuun is produced.

Question 17.
Write names of the substances which got reduced and oxidized.
1. SO₂ + 3H₂S → 2H₃O + 3S
Answer:
In SO₂, S is reduced and in H₂S, S is oxidized.

2. 2Al + 3HCl → 2AlCl₂ + 3H₂
Answer:
Aluminium is reduced and chlorine is oxidized.

3. 2H₂S + SO₂ → 3S + 2H₂O
Answer:
Hydrogen is oxidised and sulphur is reduced.

4. Zn + 2AgNOa → An (NO₃)₂ + 3Ag
Answer:
Zinc is oxidised and silver is reduced.

5. H₂ + CuO → Cu + H₂O.
Answer:
Hydrogen is oxidised and copper is reduced.

Question 18.
What does a complete chemical equation represent and why is it necessary to balance a chemical equation?
Answer:
A complete chemical equation represents reactants, products and their physical state in a symbolic form.
A chemical equation is balanced so that number of atoms of every element in reactants and products becomes equal. Therefore it is necessary to balance the chemical equation.

Question 19.
What type of reactions are combustion of coal and formation of water? Represent by chemical equation.
Answer:
1. Combustion of Coal:
C(s) + O₂ (g) → CO₂ (g)

2. Formation of water from H₂ and O₂ :
2H₂(g) + O₂(g) → 2H₂O(l)

Question 20.
How is dissociation reaction different from combination reaction?
Answer:
In a combination reaction two or more than two substance combine to give a single new substance where as in dissociation reaction a single substance breaks or dissociates into two or more than two new substances.

Question 21.
Give two examples of dissociation reaction.
Answer:

Question 22.
What is the difference between oxidation and reduction?
Answer:
In reaction, some substance gain or loose oxygen and hydrogen. If there is gain of oxygen or loss of hydrogen from a substance then it is called oxidation. Loss of oxygen and gain of hydrogen is called reduction.

Question 23.
Give two examples of corrosion.
Answer:
Examples of corrosion are :

1. black coating on silver
2. green coating on copper.

Question 24.
Which type of reaction is shown in figure given below and define it.
Answer:
Displacement Reaction. It is a reaction in which more active element (metal or non-metal) displaces less active element (metal or non-metal) from its solution of its compound.

Question 25.
What is shown in the figure given ahead? Also indicate 1 and 2 in the figure .
Answer:
The figure represents electro-lysis of water :

1. Oxygen gas
2. Hydrogen gas

Question 26.
The following diagram displays a chemical reaction. Observe carefully and answer the following questions:

(i) Identify the type of chemical reaction.
Answer:
Photochemical decomposition

(ii) Write the chemical equations.
Answer:

Very Short Answer Type Questions

Question 1.
What do we get on the combustion of magnesium ribbon?
Answer:
We get a white powder of Magnesium oxide.

Question 2.
What is law of conservation of mass?
Answer:
In any chemical reaction, mass can neither be created nor destroyed.

Question 3.
Define balanced chemical equation.
Answer:
If number of atoms of each element before and after the chemical reaction are equal, then such a chemical reaction is balanced equation.

Question 4.
Give one example of balanced equation.
Answer:
3 Fe + 4H₂O → Fe₃O₄ + 4H₂.

Question 5.
If (g) is written with water, then what does it represent?
Answer:
Water is in the form of vapour or steam.

Question 6.
Sometimes we show the conditions of a reaction like pressure, temperature, catalyst etc. where do we write it.
Answer:
Above and below the arrow.

Question 7.
How does a new substance form in a chemical reaction?
Answer:
By breaking and making of bonds between atoms.

Question 8.
Define combination reaction.
Answer:
A reaction in which two or more than two reactants combine to give single product is called combination reaction.

Question 9.
What is the use of slaked lime?
Answer:
For whitewashing the buildings.

Question 10.
Write chemical formula for Marble.
Answer:
CaCO₃.

Question 11.
What do we get on the combustion of natural gas?
Answer:
CO₂, H₂O and energy.

Question 12.
Write formula for ferrous sulphate.
Answer:
FeSO₄.7H₂O.

Question 13.
What is formed of grey colour from silver chloride in sun light?
Answer:
Silver metal.

Question 14.

Where is above reaction used?
Answer:
Black and white photography.

Question 15.
Why after some time shining iron articles become dull?
Answer:
Due to rust.

Question 16.
What is the colour of rust coating on iron?
Answer:
Brown colour.

Question 17.
What is corrosion?
Answer:
When a metal comes in contact with moisture, acid etc. it gets corroded and the process is called corrosion.

Question 18.
What is the colour of coating on silver due to corrosion?
Answer:
Black coating.

Question 19.
What is the colour of coating on copper due to corrosion?
Answer:
Green coating.

Question 20.
Due to which process, there is a change in smell and taste of food items which contain fat and oils?
Answer:
This change is due to oxidation and is called rancidity.

Question 21.
What do the manufacturer of chips flush in the packets of chips to prevent oxidation?
Answer:
Nitrogen gas.

Question 22.
What is the colour of coating of copper(II) oxide?
Answer:
Black colour.

Question 23.
What is other name of oxidation-reduction reaction.
Answer:
Redox reaction.

Question 24.
When does oxidation of substance take place in a reaction?
Answer:
When there is gain of O₂ or loss of H₂.

Question 25.
When does reduction of a substance take place in a reaction?
Answer:
When there is loss of O₂ or gain of H₂.

Question 26.
White coloured silver chloride change to which colour in sunlight?
Answer:
In grey colour.

Question 27.
Give one example of endothermic reaction.
Answer:
3AgCl(s) → 2Ag(s) + Cl₂(g)

Question 28.
In w hat calcium carbonate dissociate when heat is given to it?
Answer:
Calcium oxide and carbon dioxide.

Question 29.
Write chemical formula for slaked lime.
Answer:
Ca(OH)₂.

Question 30.
What is special there in potato, rice and bread?
Answer:
Carbohydrate.

Question 31.
What do we get on the decomposition of carbohydrate?
Answer:
Glucose.

Question 32.
Write the reaction for combination of natural gas?
Answer:
CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g) + energy.

Question 33.
What type of reaction is combination of coal and formation of water from H₂ and O₂?
Answer:
Combination reaction.

Question 34.

What is A in above reaction.
Answer:
Chlorophyll.

Question 35.
What is skeletal chemical equation?
Answer:
If in a chemical reaction, number of atoms of each element on left hand side is not equal to number of atoms of each element on right hand side such a reaction is called skeletal chemical equation.

Question 36.
What are products?
Answer:
In a chemical reaction new substances are formed which are known as products.

Question 37.
What are reactants?
Answer:
Those substances which take part in a chemical reaction and undergo chemical changes are called reactants.

Question 38.
What is reduction reaction?
Answer:
It is a reaction in which there is loss of oxygen or gain of hydrogen.

Question 39.
What is oxidation reaction?
Answer:
It is reaction in which there is loss of hydrogen or gain of oxygen.

Question 40.
If in a reaction one reactant is reduced and other is oxidised, what is name of such a reaction?
Answer:
Redox reaction.

Multiple Choice Questions:

Question 1.
The chemical reaction given below represents :
BaCl₂(aq) + Na₂SO₄(aq) →
BaSO₄(s) + 2 NaCl(aq)
(A) Decomposition reaction
(B) Displacement reaction
(C) Combination reaction
(D) Double diplacement reaction.
Answer:
(D) Double displacement reaction

Question 2.
The chemical reaction in which heat energy is given out is called:
(A) Exothermic reaction
(B) Endothermic reaction
(C) Polymerisation reaction
(D) All.
Answer:
(A) Exothermic reaction

Question 3.
During electrolysis, hydrogen and oxygen are produced in the ratio by volume :
(A) 2:1
(B) 1:1
(C) 2:2
(D) 4:1.
Answer:
(A) 2: 1.

Question 4.
The chemical formula of rust is:
(A) Fe₂O₃
(B) FeCO₃
(C) Fe₂O₃ .xH₂O
(D) FeCO₃ xH₂O.
Answer:
(C) Fe₂O₃ .xH₂O

Question 5.
Which is an example of a decomposition reaction?

Answer:

Question 6.
Redox reaction involves:
(A) Oxidation
(B) Reduction
(C) Both oxidation and reduction
(D) None.
Answer:
(C) Both oxidation and reduction

Question 7.
In a packet of chips oxygen is replaced by gas:
(A) CO₂
(B) SO₂
(C) N₂
(D) O₃.
Answer:
(C) N₂

Question 8.
Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)
What type of chemical reaction is shown by the above equation?
(A) Combination reaction
(B) Dissociation reaction
(C) Displacement reaction
(D) Double displacement reaction.
Answer:
(C) Displacement reaction.

Fill in the blanks:

Question 1.
Complete the following chemical equation.

Answer:

Question 2.
Respiration is an ________ reaction.
Answer:
Respiration is an exothermic reaction.

Question 3.
Rusting of iron is a ________ reaction.
Answer:
Rusting iron is a redox reaction.

Punjab State Board PSEB 10th Class Agriculture Book Solutions Chapter 11 Plant Clinic Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Agriculture Chapter 11 Plant Clinic

Agriculture Guide for Class 10 PSEB Plant Clinic Textbook Questions and Answers

(A) Answer in one-two words:

Question 1.
In which year plant clinic was established at Punjab Agricultural University, Ludhiana?
Answer:
In 1993.

Question 2.
How many plant clinics have been established by Punjab Agricultural University, Ludhiana in Punjab?
Answer:
Plant clinics are running at 18 Krishi Vigyan Kendras (KVKS) in various districts and four at regional research stations Abohar, Bathinda and Gurdaspur and Department of Fruit science, PAU, Ludhiana.

Question 3.
Where is plant clinic located at PAU?
Answer:
PAU clock tower, located near gate no. 1 at PAU campus.

Question 4.
Name any two instruments/tool being used in the plant at clinics?
Answer:
Computer, Microscope, scissors, knife etc.

Question 5.
Name the principle based on which the exact quantity of pesticides is calculated to control insect pests on different crops.
Answer:
Economic threshold level.

Question 6.
Name the instrument with the help of which one can observe the pictures on slides.
Answer:
Projector.

Question 7.
Name the tool used to observe the small disease specimens under field conditions.
Answer:
Microscope.

Question 8.
Name any two chemicals used for preservation of diseased plant specimens.
Answer:
Formalin, acetic acid.

Question 9.
Mention the email address of plant clinic located at Punjab Agricultural University, Ludhiana.
Answer:
plantclinic@pau.edu.

Question 10.
Mention the telephone number of plant clinic situated at PAU, Ludhiana.
Answer:
0161-240-1960 with extension 417. Mobile number: 9463048181.

(B) Answer in one-two sentences:

Question 1.
What is plant clinic?
Answer:
Plant clinic is a place where diagnosis and remedial measures for diseased plants, nutrient deficiency, insect attack etc. are provided to the farmers.

Question 2.
What are the advantages of Plant Clinic?
Answer:

• Diagnosis and remedial measures for plants are provided.
• Various experts are available at all times in the plant clinic for quick redressal of day to day problems faced by farmers.
• Farmers can get solutions to their problems through email, mobile phone, whatsapp.

Question 3.
How plant clinic differ from human hospitals?
Answer:
In human hospitals, diseases of human beings are identified and treated. Whereas in plant clinic besides treating diseased plants, training and education to identify diseased plants is also given.

Question 4.
Mention the disiciplines / subjects used for the identification of plant specimens.
Answer:
In these clinics attack of disease, nutrient deficiency, insect attack and other reasons which are harming plants are studied. Disciplines which are used to identify plant, specimen etc. at plant clinic are plant pathology, entomology, soil sciences, agronomy etc.

Question 5.
Enlist the equipments being used in plant clinic.
Answer:
Following equipments are required at plant clinic:
Microscope, magnifying lenses, chemicals, incubator, scissors, knife, computer, photo camera, projector, books, etc.

Question 6.
What is the importance of microscope in plant clinic?
Answer:
Plant is dissected to see the symptoms of disease by using microscope. Actual colour, small identification marks etc. are also seen by using microscope.

Question 7.
What do you understand from the term “Economic Threshold Level”?
Answer:
To protect plants from diseases and insects, fertilizers and insecticides should be used after properly calculating the required dose of these. When number of insects increased upto a specific number or affect a specified number of plants of the crop. Spray of pesticide should start after this level has reached. This way crop as well as farmers will get some benefit. This is known as economic threshold level.

Question 8.
Comment on the use of computer in plant clinic.
Answer:
Some specimens cannot be preserved either wet or dry. Such samples are scanned and stored in computer. These can be used when needed.

Question 9.
How incubator is useful in diagnosis of microorganisms in plants?
Answer:
Media after inoculation with pathogen is placed in incubator which is set at appropriate temperature and proper moisture is provided for the proper growth of pathogen. This is used for identification of other organisms also.

Question 10.
Enlist the chemicals required for the preservation of plant specimen in glass jars.
Answer:
For this work formalin, alcohol etc. is used.

(C) Answer in five-six sentences:

Question 1.
Describe the mobile diagnosis-cum-exhibition van.
Answer:
To make the reach of plant clinics upto the villages, plant clinics have mobile diagnostics cum exhibition van. This van has the facilities in it for diagnosis and for exhibition. It has various equipments in it and it has the facility to show movies of technical know how to farmers, Agricultural experts provide remedies at the spot after testing and knowing their problems. Farmers are gaining a lot from this van.

Question 2.
What is the use of camera and Liquid Crystal Display (LCD) projector in plant clinic?
Answer:
Camera is used to take photographs of diseased plants. These photographs and slides are kept safe in the plant clinic. These are shown to the students for further reference. Scientists can also take help from these photos. Projector is used to see these slides. It can show enlarged view of photos and slides.

Question 3.
Define PAU doots and KMAS service of plant clinic.
Answer:
PAU doots is a new service introduced by clinic plants in which some farmers are enrolled as ‘PAU doots’ who are given the responsibility to disseminate the agriculture technology: These doots disseminate the information, which they get regularly through mobile messages and emails, to the fellow farmers using public address system.

KMAS is Kisan Mobile Advisory Service which is provided by Krishi Vigyan Kendras (KVKs) to the farmers for adopting advanced and new agricultural practices at their field. Messages are sent to the fellow farmers for spreading the technology related information.

Question 4.
What is touch screen Kisok and farmer service centre?
Answer:
Plant clinic has a computerized touch screen Kisok which is called information booth. It pictorially explains the production and protection technology of rabi and Kharif crops from sowing till harvesting. Plant clinic was made a part of Farmer Service Centre (FSC) in 1999 and now it is known as agricultural technology information centre. Various types of problem of allied activities related to agriculture are taken. This is very helpful centre for the farmer.

Question 5.
Describe the services provided by plant clinic to the farmers. Or What are the advantages of plant clinic?
Answer:

• In Plant Clinic identification of deficiency of nutritional elements in plants is done and also identification of harmful insects is also done.
• After identifying the symptoms of the diseased plarfts brought from the fields, methods to prevent diseases are suggested on the spot.
• In Plant Clinic training is given to identify the symptoms of diseases and insects.
• Training is given to calculate the required amount of fertilizers and insecticides etc. to be applied to the crop so that unnecessary expenditure can be avoided.
• Training is also given about the economic threshold of main insects of different crops. This helps in knowing exact amount of fertilizers and insecticides to be used or applied.
• Training for using different types of spray pumps and other agriculture implements is also given.
• Students are shown various types of diseased plants and are trained to treat such plants. This help in reducing the expenditure of the fanners.
• Photographs of various types of implements, fertilizers, pumps, plant sample, seed and other items used for studying plants are kept at the plant clinic.

PSEB 10th Class Agriculture Guide Plant Clinic Important Questions and Answers

Multiple Choice Questions

Question 1.
Name of chemical used for preservation of diseased plant specimens.
(a) Formalin
(b) Gulocose
(c) Sodium bromide
(d) None.
Answer:
(a) Formalin

Question 2.
In which year plant clinic was established in. PAU?
(a) 2010
(b) 1993
(c) 1980
(d) 1955.
Answer:
(b) 1993

Question 3.
Which tool is tised to diagnose micro organisms in plants?
(a) microscope
(b) incubation
(c) Projector
(d) All.
Answer:
(b) incubation

Question 4.
In how many Krishi Vigyan Kendras (KVKs) are plant clinics working?
(a) 1
(b) 27
(c) 18
(d) 22.
Answer:
(c) 18

Question 5.
What is the e-mail address of plant clinic of Punjab Agriculture University?
(a) www.gadvasu.in
(b) www.pddb.in
(c) plantclinic@pau.edu
(d) www.pau.edu.
Answer:
(c) plantclinic@pau.edu

Question 6.
Mention the landline telephone number of plant clinic situated at Punjab Agricultural University.
(a) 0161-2401960 Extension-417
(b) 94630-48181
(c) plantclinic@pau.edu
(d) www.pau.edu.
Answer:
(a) 0161-2401960 Extension-417

True False:

1. PAU established Central Plant Clinic at Ludhiana in 1993.
Answer:
True

2. Various types of equipments and apparatus are required in the plant clinic.
Answer:
True

3. No chemicals are required in plant clinic.
Answer:
False

4. e-mail address of plant clinic at Punjab Agricultural University is plantclinic@pau.edu.
Answer:
True

Fill in the blanks:

1. To see various symptoms of disease, we use ………….. .
Answer:
microscope

2. One of the chemical used to preserve fresh symptoms of various plants is …………. .
Answer:
formaldehyde

3. Computer, ………… are important part of plant clinic.
Answer:
scanners

4. Plants are dissected using knife, ……………..etc.
Answer:
scissors.

Very Short Answer Type Questions

Question 1.
Give one reason due to which yield is reduced.
Answer:
Deficiency of nutrients, diseases, attack of insects.

Question 2.
Which instrument is used to see the symptoms of diseases?
Answer:
Microscope.

Question 3.
What is used for disection of plants?
Answer:
Knife, scissors etc.

Question 4.
Which equipment is used to observe micro organisms?
Answer:
Incubator.

Question 5.
At which mobile number one can contact plant clinic?
Answer:
9463048181.

Question 6.
Which type of van is used by plant clinic at PAU for giving technical knowledge to villagers?
Answer:
Mobile diagnostic cum exhibition van.

Question 7.
Write name of any one chemical which is used in plant clinic?
Answer:
Formalin.

Short Answer Type Questions

Question 1.
What is the need of knife in the plant clinic?
Answer:
Knife is used to dissect the plant so that it can be viewed under the microscope.

Question 2.
What is the use of magnifying lens in plant clinic?
Answer:
This is used Ip see small parts of plants, insects and other smaller organism and to identify them.

Question 3.
Which service has been started by plant clinic so as to reach the villagers?
Answer:
PAU doot and KMAS service has been started. Farmers can register their email and mobile number with the plant clinic to” get benefits.

Long Answer Type Questions

Question 1.
What is meant by economic threshold? Describe in detail.
Answer:
Before applying insecticides, their exact amount required for the particular crop is first calculated. This way plants can get maximum benefit and expenditure is also minimum. Many problems are created if insecticides f are used in excess of what is required or if these are unnecessarily used. e.g. insects become resistant to the use of insecticides, these become habitual rather than dying, friendly insects are also killed, the insects which were not harmful earlier may start harming the crop, whole of the environment gets polluted.

Every year the same insect does not attack the crop to the same extent. On one year the attack is intense on the other year it may be moderate or mild. Therefore, one should take proper care while using these drags. Insecticides should be used only when the number of insects reach a particular level for a given crop. This way plant get more benefit and expenditure is also lowered.

Number of insects should not be allowed to increase from the specified value and do not allow these to damage the crop. Farmers should not get monetary loss due to unnecessary use of drugs. Sometime the signs of attack are counted and not the number of insects e.g. Stemborer in rice. Its attacked sites are counted and not actual number of insects.

Question 2.
Criticise the future of economic clinics.
Answer:
This is a competition age. Therefore, farmers should not allow the nutrient deficiencies to occur in their crops and also should take proper measures to protect the crop from diseases. This way he can earn more profit. The agriculture is now not limited only to state or country but has extended to international level. Produce has to be exported to other countries.

If produce is of good quality one can earn more profit. Help from plant clinic can be taken to maintain the proper quality of the crop. Nutrient deficiencies can be checked and proper fertilizers can be used to overcome the deficiencies. Amount of insecticide or fertilizers to be used can be calculated and expenditure on these poisons can be reduced. Unnecessary use of these poisons also harm the whole of environment Therefore, plant clinics have an important role to play in future.

Question 3.
Which facilities are available at plant clinic?
Answer:

• Farmers are given technical knowledge at plant clinics.
• Diagonsis of diseases is done, their symptoms are noted. Damage of crop by insects is also estimated.
• Soil and water testing facility is also available.
• Farmers can contact plant clinic through telephone, e-mail and whats app and can get solution to their problems.
• Plant clinic has a diagnostic cum exhibition mobile van, which is used to reach villagers and films are shown to farmers having technical information.
• PAU has started PAU messengers and KMAS service. Farmers can register their phone no. and e-mail with the plant clinic.

Question 4.
Explain the need of plant clinic by telling its history.
Answer:
For the last few years there is an increase in number of students from cities who are seeking admission in higher education courses related to agriculture. These students do not have much of practical knowledge about agriculture works and when they go to the field work after getting higher education degrees, they face so many practical problems.

First plant disease clinic was set up by PAU Ludhiana in 1978 and later on PAU Ludhiana established central plant clinic in 1993. In different districts there are 18 agriculture science centres, where plant clinics are also running. These clinics have proved very useful for the students. Because of this principle farmers are getting knowledge and information about the nutritional deficiencies in their crops and protection against diseases, thus they are earning more profit.

Question 5.
What is plant clinic? What is the use of computer in plant clinic?
Answer:
Do it yourself.

Punjab State Board PSEB 10th Class Agriculture Book Solutions Chapter 10 Beneficial and Harmful Animals in Agriculture Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Agriculture Chapter 10 Beneficial and Harmful Animals in Agriculture

Agriculture Guide for Class 10 PSEB Beneficial and Harmful Animals in Agriculture Textbook Questions and Answers

(A) Answer in one-two words:

Question 1.
How many species of rodents are there in Punjab?
Answer:
8 types.

Question 2.
In which area of Punjab Indian bush rat is found?
Answer:
Dry and sandy areas.

Question 3.
How much damage is caused to germinating winter maize by rodents?
Answer:
10.7%.

Question 4.
At how many locations poison bait should be placed in one acre?
Answer:
At 40 locations at the rate of 10 grams of bait at a point

Question 5.
Name the two reodent eating beneficial birds.
Answer:
Owl and eagle.

Question 6.
Name the bird causing maximum damage to crops. Or Which is the most harmful bird in agriculture?
Answer:
Parrot (Rose ringed parakeet)

Question 7.
How much should be the height of scare crow from the crop?
Answer:
One metre more than the height of crop.

Question 8.
Name any one chemical used for killing rodents.
Answer:
Zinc phosphide.

Question 9.
Where does lapwing make its nest?
Answer:
On the ground.

Question 10.
What does Hoopoe eat its diet?
Answer:
Insects.

(B) Answer in one-two sentences:

Question 1.
Why we need to protect the agricultural products from harmful animals?
Answer:
Development in the agriculture field can be maintained if agriculture produce is stored properly and protected from harmful animals, birds etc. It is necessary to protect the produce from the pests.

Question 2.
Describe the method of pre-baiting for rodents.
Answer:
To trap more rodents it becomes necessary to prebait the rodents. For this purpose place bait in each cage consisting of 10 to 15 gram pearl millet, sorghum or cracked wheat, which contains two per cent of powdered sugar and two ppr cent of groundnut or sunflower oil, for 2-3 days.

Question 3.
How to reduce the ill effect of Bromadiolone in human being?
Answer:
Effect of bromadiolone can be reduced by using vitamin K as antidote. Use this vitamin under the supervision of ajdoctor.

Question 4.
How the anti rat campaign can help in eradication of rats at village level? .
Answer:
It is of no use to eradicate rats in a smaller area. Because rats will come again from the neighbouring field or area. To get best results there should be rat killing campaign at village level. Under this campaign rodents are killed collectively in whole of the village at all the locations e.g. in orchards, in cultivated, uncultivated, forestry land etc.

Question 5.
What do you mean by scarecrow? What is its role in crop protection?
Answer:
Take a small pitcher, draw human face on it using colour. This pitcher is made to hang on the sticks fixed vertically in the fields. Put on human clothes on this structure. This is known as scarecrow. Birds consider this structure as human being and do not come to the field.

Question 6.
How the oil seed crop can be protected from parakeet damage?
Answer:
Parrot has little communal association with crows. Therefore to keep the parrots away from the fields, hang 1-2 dead crows/their dumies at sites of frequent bird damage. This way we can protect oilseed crops from parrots.

Question 7.
Why the crop should not be sown at the place having dense trees?
Answer:
Birds have their nests on the trees. If maize and sunflower crops are sown near such sites where birds come and go very easily and very frequently then birds can easily damage the crop. Therefore, crop should not be sown near the places having dense trees.

Question 8.
How the beneficial birds help farmers in protecting the crops?
Answer:
Rats are the prey for owls, hawks, falcon, eagles etc. Birds like drongos, blue joy, cattle egret, lapwings etc. are insects eating birds. These eat many of the harmful insects from the fields.

Question 9.
How do you identify the Cattle Egret?
Answer:
It is a white coloured bird and its beak is yellow. This bird is seen preying on insects behind the tractor or oxen during ploughing.

Question 10.
What do you know about the precautions to be taken during use of poisonous bait?
Answer:
Precautions while-using poisonous baits:

• Use a stick or Khurpa for mixing the ingredients of bait while preparing. Otherwise use rubber gloves. Protect eyes, nose and mouth from the bait;
• Keep rodenticides and poisonous bait away from the reach of children and domestic animals.
• Never prepare baits in household utensils.
• Use polythene bags for carrying baits and after use bury these bags under the earth.
• Killed rats along with baits should be buried deep under the earth.
• Zinc phosphide is very poisonous for humans. In case of accidental ingestion induce vomitting by inserting fingers in the mouth upto throat and rash to doctor.

(C) Answer in five-six sentences:

Question 1.
How many types of rodents are there in Punjab? Describe the rodent species found in various areas of Punjab.
Answer:
In Punjab there are 8 species of rats and mice. Indian gerbil, Indian bush rat, Indian mole rat, soft furred field rat, short tailed mole rat, house mouse, brown spiny mouse, field mouse. The Indian mole rat can damage sugarcane and rice-wheat at the time of germinating. Indian mole rat is found mostly in bet area whereas Indian gerbil and Indian bush rat are found in Kandi region (district Hoshiarpur)

Question 2.
Describe the two methods of preparation of poisonous bait.
Answer:
1. 2% zinc phosphide bait:
Take 1 kg of bajra or sorghum or cracked wheat with 20 gram of vegetable oil (sunflower or groundnut oil), and 25 gram of zinc phosphide. Mix all these materials thoroughly. Always prepare fresh bait and never add water to this bait.

2. 0.005% Bromadiolone bait:
Take 20 gram of vegetable oil, (sunflower or groundnut oil), 20 gram powdered sugar and 20 gram bromadiolone powder and 1 kg of cracked wheat or any other cereal flour. Mix this material properly, bait is ready for use.

Question 3.
How to manage rodents by integrated management methods?
Answer:
Using only one method to control rats is not very effective. Rats multiply themselves quickly by giving birth to offsprings. Therefore, use more than one method to kill rats. Rats coming out from flooded burrows should be killed using sticks. After sowing of a crop use chemical methods to kill rats. After pre-baiting also put some gas tablets in the burrows. After zinc phosphide if needed use bromadiolone.

Question 4.
Describe the traditional methods used for protection of crops from birds.
Answer:

• Sow Dhaincha and Bajra near the costly crops to save the crops from birds. Birds like to eat bajra and dhaincha. Birds prefer these crops as their feed and main crop is saved.
• Do not sow crops like sunflower near the places where birds usually visit e.g. near the electricity wires and near the dense trees.
• To save maize and sunflower from Parrots, sow these crops at least in two-three acres of area. Parrots do not go inside the crop and does not harm the crop to large extent.

Question 5.
Describe the mechanical method of protecting crop from birds.
Answer:
1. Making explosions: Make false gun shots at different time intervals to scare the birds.

2. Using scarecrow:
Take a small pitcher, draw human face on it using colour. This pitcher is made to hang on the sticks fixed vertically in the fields. Put on human clothes on this structure. This is known as scarecrow. Birds consider this structure as human being and do not come to the field.

3. Hanging dead crows:
Parrot has little communal association with crows. Therefore, to keep the parrots away from the fields, hang 1-2 dead crows/their dumies at sites of frequent bird damage. This way we protect oilseed crops from parrots.

4. Using rope-crackers:
Tie fire crackers on a rope at 6-8 inch distance. Ignite the lower end of the rope. Explosions caused by fire crackers at different intervals scare the birds and the birds fly away. Fix the rope in the centre at the time of germination and at the boundaries of the field at the time of maturity.

PSEB 10th Class Agriculture Guide Beneficial and Harmful Animals in Agriculture Important Questions and Answers

Multiple Choice Questions

Question 1.
Friendly birds are:
(a) Lapwing
(b) Blue Joy
(c) Drongo
(d) All.
Answers:
(d) All.

Question 2.
Rats eaten by an owl in a day.
(a) 4-5
(b) 8-10
(c) 1-2
(d) All.
Answers:
(a) 4-5

Question 3.
Where does red mattled lapwing (tatihri) make its nest?
(a) on ground
(b) on trees
(c) in water
(d) None.
Answers:
(a) on ground

Question 4.
Chemical used to kill rats is:
(a) Sodium
(b) Potassium chloride
(c) Zinc phosphide
(d) All.
Answers:
(c) Zinc phosphide

Question 5.
How many types of birds are found in Punjab?
(a) 100
(b) 50
(c) 300
(d) 50.
Answers:
(c) 300

Question 6.
Which bird makes its nest in the cavities of the trees?
(a) Hoopoe
(b) Red-wattled lapwing
(c) Cattle egret
(d) House sparrow.
Answers:
(a) Hoopoe

Question 7.
Which bird makes its nest on ground?
(a) Hoopoe
(b) Red-watded Lapwing
(c) Cattle Egret
(d) Blue Joy.
Answers:
(b) Red-watded Lapwing

Question 8.
Which bird makes its nest in groups on the top of the trees?
(a) Hoopoe
(b) Red-wattled lapwing
(c) Cattle egret
(d) Owl.
Answers:
(c) Cattle egret

Question 9.
How much damage is caused to sprouting wheat by rodents?
(a) 2.9%
(b) 10.7%
(c) 4.5%
(d) 1.1%.
Answers:
(a) 2.9%

True False:

1. Blue Joy has insects as its main diet.
Answers:
True

2. Eight type of rodents and mice are found in the fields of Punjab.
Answers:
True

3. Rose-ringed parakeet is most harmful bird in the field of agriculture.
Answers:
True

4. Zinc Phoshide is used to kill cats.
Answers:
True

5. Owl, Falcon are friendly birds for a farmer.
Answers:
True

Fill in the blanks:

1. Scare crow should be atleast ………………… higher than the crop.
Answers:
one metre

2. For trapping rodents place ………………….. traps per acre in the field.
Answers:
16

3. ………………………….. percent of total bird species in India are useful to agriculture.
Answers:
3. 98

4. ………………………. bird has a yellow beak.
Answers:
Cattle egret.

Very Short Answer Type Questions

Question 1.
Where does rats live?
Answer:
Rats live in Burrows.

Question 2.
Which species of rats are found in areas of sugarcane and wheat rice and bet areas?
Answer:
Indian mole rat.

Question 3.
Which rat is found in Kandi region?
Answer:
Gerbil rat.

Question 4.
Which rats are found in Kandi region?
Answer:
Indian Bush rats.

Question 5.
How much damage is done by rats at the time of sprouting and maturity?
Answer:
At the time of sprouting is 2.9%. At the time of maturity is 4.5%.

Question 6.
How much damage is done to peas by rats at the time of maturity?
Answer:
1.1%.

Question 7.
How much damage is done by rats in bet area at the time of maturity of wheat?
Answer:
25%.

Question 8.
How will you kill rats which are coming out of flooded burrows?
Answer:
Kill with sticks.

Question 9.
How many traps per acre should be placed for trapping rats?
Answer:
16 traps.

Question 10.
After how many days cages should be used again for trapping rats?
Answer:
After 30 days.

Question 11.
For how much area one kg of zinc phosphide bait be used?
Answer:
2.5 acre.

Question 12.
What is natural method to control rats?
Answer:
Rats are the prey for owls, kites, hawks, falcons, eagles, snakes, cats, mongooses, jackals, etc.

Question 13.
How many species of birds are found in Punjab?
Answer:
300 species.

Question 14.
What is the worth in Rs. of rice which are eaten by doves, Pigeons and weaving bird?
Answer:
Worth rupees 2 crore.

Question 15.
After how many days should the direction, clothes and location of the scarecrow be changed?
Answer:
After ten days.

Question 16.
How many rats are eaten by an owl?
Answer:
4-5 rats in a day.

Question 17.
For how many times a single pair of house sparrow feeds its chick?
Answer:
250 times.

Short Answer Type Questions

Question 1.
What should we do to save birds around us?
Answer:

• We should plant conventional trees like, Banyan, Peepal, Kikkar, Tahli, Toot etc. around our living area.
• We should provide place for nests by placing wooden or earthen pots wherever possible.

Question 2.
Write about Neelkanth.
Answer:
It has pale blue abdomen and breast is rufous brown. It is of the size of blue rock pigeon. It feeds on insects. Its nest is in the cavities of the trees.

Question 3.
Write about Red-wattled Lapwing.
Answer:
Its head, bieast and neck are black in colour. It is bronze brown from above and white from below. It feeds on insects and snails. It makes its nest on ground.

Question 4.
How are the crops protected by using scarecrows (Darna)?
Answer:
See in above questions.

Long Answer Type Questions

Question 1.
Give chemical methods of killing rodents (rats).
Answer:
See above question.

Question 2.
Give mechanical methods to protect crops from rats.
Answer:
Following mechanical methods are used:

• Killing rats-After harvesting, at the time of Rauni rats come out from the flooded burrows which are killed by sticks.
• Using cage/traps-See above questions.
• Using bait-See above questions.

Question 3.
How traps and cages can be used to protect crop from rodents?
Answer:
Kill the trapped rats by drowning in water and the interval between two trapping in the same location should not be less than 30 days. P.A.U. has developed double chambered multi-catch trap with tunnel type entrance. Many rats can be trapped at a time. Place 16 traps for an acre at runways and activity sites of rats in the fields, also place traps in homes, poultry farms, godowns, stores etc. Place one trap for 4 to 8 square metre along the walls, comers of rooms, grain storing places and behind the boxes.

In cold stores wrap the traps in newspapers before placing. For catching rats pre-baiting is done. For this purpose put in each cage/trap bait consisting of 10 to 15 grams of bajra or sorghum or cracked wheat, which contains 2% of powdered sugar and 2% of groundnut or sunflower oil. This should be done for 2-3 days. Thus by using traps crops can be saved from damage by rats.

Question 4.
Why we should not kill birds useful for crops?
Answer:
Useful birds include insectivorous and rodentivorous birds. They feed insects to their young ones. Predatory birds; like, owl, eagle, falcons etc. eat rats and mice. An owl can eat 4-5 rats a day. These birds help the farmers by killing insects and rodents. We should not kill such useful birds.

Question 5.
What do you know about the precautions to be taken during the uses of poison bait?
Answer:

• Poison bait should be kept away from the reach of children, domestic animals, pets and birds.
• Save the mouth, eyes and skin from the poison b&t.
• Never use household utensils for the preparation of poison bait.
• Use polythene bags for storage and carrying these poison baits. Bury them after use.
• Collect and burry the left over poison bait and the dead rats aways from the field.

Question 6.
How will you identify the woodpecker?
Answer:
It has a long beak, which has a little bend. It has lines on its feathers, body and tail of white and black colour. It has cockscomb also.

Punjab State Board PSEB 10th Class Agriculture Book Solutions Chapter 9 Certified Seed Production Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Agriculture Chapter 9 Certified Seed Production

Agriculture Guide for Class 10 PSEB Certified Seed Production Textbook Questions and Answers

(A) Answer in one-two words:

Question 1.
Write names of two Mexican wheat varieties which were introduced in India in sixties.
Answer:
Lerma Roso, Sonora-64.

Question 2.
Write name of machine which is used for cleaning of seed.
Answer:
Seed grader.

Question 3.
Write name of two recently recommended varieties of wheat.
Answer:
W.H. 1105, PBW 621.

Question 4.
How many tags are stitched on a bag of certified seed?
Answer:
Two – green and blue.

Question 5.
What is the colour of tag which is used to label foundation seed?
Answer:
White tag.

Question 6.
Write full form of T.L.
Answer:
Truthfully Labelled.

Question 7.
In which year seed act was passed?
Answer:
In the year 1966.

Question 8.
What is the minimum germination per cent of certified wheat seed?
Answer:
Not less than 85%.

Question 9.
Give minimum purity of certified seeds of rice.
Answer:
98%.

Question 10.
Write one important yield contributary hereditary trait of cotton plant.
Answer:
Number of cotton bolls, average weight of cotton bolls.

(B) Answer in one-two sentences:

Question 1.
What are the objectives of seed act? When was this regulated?
Answer:
The objective of seed act was to provide right pedigree seeds at lower cost to the farmers. This act was enacted in year 1966.

Question 2.
List two important hereditary and yield contributory traits of cotton plant.
Answer:
Heredity qualities of cotton crop are – number of cotton bolls, average weight Of cotton bolls, number of branches bearing fruit etc.

Question 3.
Define foundation seed.
Answer:
Certified seeds are produced from foundation seeds and foundation seeds shall be the progeny of breeder seeds.

Question 4.
Write full name of agency which certifies the quality of seed.
Answer:
Punjab State Seed Certification Authority has the authority to certify seeds.

Question 5.
List three important yield contributory traits of wheat plant.
Answer:
Some of the yield contributory traits of wheat plants are – number of branches per plant, number of grains per ear, weight of grains, length of ear etc.

Question 6.
Who produces breeder seed?
Answer:
The agency which has researched and discovered the variety, produces nuclear seeds and then produces breeder seed from nuclear seed.

Question 7.
List three parameters of physical quality of seeds. .
Answer:
Physical appearance qualities – colour of seed, shape, weight etc.

Question 8.
Define a certified seed.
Answer:
Those seeds which are produced according to the standards set by Punjab State Seed Certification Agency and also under their supervision are called certified seeds.

Question 9.
What is the importance of isolation distance in seed production?
Answer:
The crop which is used for seed production should be separated from the same crop species by some minimum distance. This way seed quality and standard can be maintained and affect of other crop can be avoided.

Question 10.
Why removal of off types from a seed crop is so important?
Answer:
The seed we get is of high quality and is free from mechanical mixing.

(C) Answer in five-six sentences:

Question 1.
Differentiate hereditary traits from phenotype or physical quality traits.
Answer:
Physical quality traits:
Colour of seed, shape, weight, free from breakage, free from garbage, free from weeds and free from other seeds etc. are some of qualities which a high quality seed should have.

Hereditary traits:
These are the qualities which cannot be seen externally. These are the hidden qualities, which are carried on from one crop to the other crop. These are called genetic traits. Different plants have different genetic qualities. The difference we see in different varieties of the same crop are due to genetic qualities.

Question 2.
List three important field standards in seed production.
Answer:

• Isolation of seed.crop from other crops.
• Number of off-plants in the seed crop.
• Number of diseased plants in the seed crop.

Question 3.
Explain seed standards for a certified seed production.
Answer:
There are two types of standards which are to be followed to produce certified seeds:
(1) Standards to be followed for the seed crop in the field.
(2) Standards of the seed.

(1) Standards to be followed for the seed crop in the field:

• Isolation of seed crop from other crops.
• Number of off-plants in the seed crop.
• Number of diseased plants in the seed crop.

(2) Standards of the seed:
By testing the seed in the laboratory we can check the standards. These standards are like:

• seed germination
• physical purity of seed.
• number of diseased seeds
• number of seeds of weeds in the seeds, seeds of other crops.
• moisture per cent in seed.

Question 4.
Explain procedure for certified seed production on commercial scale.
Answer:
1. One should get proper and full knowledge and information about seed production and Marketing (sound knowledge and required expertise). Such a training can be obtained from P.A.U. Ludhiana, Krishi Vigyan Kendras (KVK), department of agriculture, Punjab State Seed Certification Authority, PUNSEED etc.

2. Choosing crop whose seed is to be produced, Make a proper plan for necessary infrastructure required for seed production and marketing etc.

3. To establish a firm and get seed licence from the department of agriculture.

4. Some of the basic requirements are seed grading machine for cleaning of seed threshing floor, store, bag closer machine, bags for packing seeds.

5. We can get foundation seed from director seeds, P.A.U. Ludhiana. Bill for seed should be in the name of firm or company and it is necessary.

6. Get the crop as recommended from the foundation seed and get registered the crop with department of Punjab State Seed Certification Authority.

7. Keep on removing by pulling out the plants which are off-type plants, diseased plants, weed plants. The above mentioned department supervise/observe the crop for two-three times.

8. Harvest the crop, clean it and pack it properly. Do all these activities under the supervision of PSSCA. Put on proper tags on the seed bags.

Question 5.
List important points for starting seed production enterprise.
Answer:
Following points should followed for starting seed production enterprise:

• Choose a crop that will give good returns and is easy to produce the seeds of this crop or not.
• Choose the crop suited to the area and which can be cultivated by you.
• Choose the crop whose seed is consumed in large quantity, e.g. wheat.
• Become registered farmer with PUNSEED.
• Whichever seeds you want to produce, gain sound knowledge and expertise to produce such seeds.
• One can earn good profit by producing hybrid seeds, but it needs hardwork, proper training and patience.
• Basic infrastructure is required which is a costly affair. Basic infrastructure consists of store, threshing floor, seed grader and other machines.

PSEB 10th Class Agriculture Guide Certified Seed Production Important Questions and Answers

Multiple Choice Questions

Question 1.
Categories of seeds are:
(a) Primary
(b) Breeder
(c) Foundation and certified
(d) All.
Answers:
(d) All.

Question 2.
Which colour tag is put on the foundation seed bag?
(a) White
(b) Blue
(c) Red
(d) Yellow.
Answers:
(a) White

Question 3.
Which colour tag is put on the bag of breeder seeds?
(a) Golden
(b) White
(c) Pink
(d) Blue.
Answers:
(a) Golden

Question 4.
New varieties of wheats which are disease free:
(a) WH1105
(b) PBW621
(c) HD3086
(d) All.
Answers:
(d) All.

Question 5.
Which colour tag by Government is put on the certified seed bag?
(a) Blue
(b) Green
(c) White
(d) None.
Answers:
(a) Blue

Question 6.
Which colour tag is put on bag of breeder seeds?
(a) Golden
(b) White
(c) Pink
(d) Blue.
Answers:
(b) White

Question 7.
How many tags are put on the bag of certified seeds?
(a) 2
(b) 3
(c) 5
(d) 4.
Answers:
(a) 2

Question 8.
What should be the minimum purity of certified seeds of paddy?
(a) 98%
(b) 80%
(c) 85%
(d) 13%.
Answers:
(a) 98%

True False:

1. Hereditary traits are determined by genetic factors.
Answers:
True

2. PBW 621 is a variety of wheat.
Answers:
True

3. Bags with certified seeds bear two tags.
Answers:
True

4. Lerma Roso is a Mexican wheat variety.
Answers:
True

5. Certified seeds of rice must have minimum 98% purity.
Answers:
True

Fill in the blanks:

1. Number of tillers per plant is a trait for wheat.
Answers:
hereditary

2. Certification tags shall be of colour for foundation seed.
Answers:
white

3. The credit of green revolution goes to wheat varieties.
Answers:
Mexican

4. Bag containing seed bears a golden tag.
Answers:
breeder.

Very Short Answer Type Questions

Question 1.
When were the Mexican wheat verities cultivated for first time?
Answer:
In 1965-66. .

Question 2.
From where was green revolution started?
Answer:
From the cultivation of semi dwarf Mexican wheat varieties.

Question 3.
Write hereditary qualities of corn.
Answer:
Length and circumference of com cob, average number of grains in the com cob, average weight of 1000 grains, time for maturity etc.

Question 4.
Write about germination of certified seeds of rice.
Answer:
Germination should not be less than 80%.

Question 5.
Which tag is attached on bag of certified seed by government?
Answer:
Blue coloured tag.

Short Answer Type Questions

Question 1.
When did the farmers experience good quality seeds?
Answer:
Nearly 50 years ago when they cultivated the Mexican Semidwarf varieties of wheat and the yield was double than the previous years.

Question 2.
What is seed?
Answer:
Some grains or some other vegetative parts of a plant e.g. roots, stem cuttings, bulbs, sukers etc. which can be used to grow new plants. These all are considered as seeds.

Question 3.
Give properties of certified seeds.
Answer:
Certified seeds have following qualities. These seeds should be of

• definite purity
• free from diseases and seeds of weeds
• definite germination.

Question 4.
Write possible qualities of certified seeds of wheat.
Answer:

• Germination – pot less than 85% .
• Purity – not less than 98%
• Moisture content – not more than 12%.

Question 5.
What information we get from green tag fixed on bags of certified seeds?
Answer:
Green Tag has the following information about the seed germination, purity, diseases and other standards.

Question 6.
Where is the head office of Punjab State See Certification Agency and where is the zonal office?
Answer:
Head office is at SCO 837-838 Sec. 22 A, Chandigarh and regional offices at Ludhiana, Jalandhar, Kotkpura.

Question 7.
What is the process to reach the certified seed?
Answer:
We get breeder seed from the nuclear seed, foundation seed from breeder seed then certified seed from the foundation seed.

Question 8.
What are the various tags attached to different seed bags?
Answer:
Yellow tag on breeder seed, White tag on foundation seed, Blue tag on certified seed.

Question 9.
How many types of seeds are there according to Seed act?
Answer:
There are four types of seeds – Nuclear seeds, Breeder seeds, Foundation seeds, Certified seeds.

Question 10.
What do you know about T.L. seed?
Answer:
If seed is not certified but otherwise it conforms to all seed and field standards it is called T.L. (truthfully labelled) seed. Such seeds should have standards like – hereditary purity, germination, moisture content as per the standards etc.

Long Answer Type Questions

Question 1.
Write about possibilities of profit and risk in the enterprise of seed production.
Answer:
The enterprise of certified seeds production is profitable. Such seeds have more selling price than the other seeds. But there is some initial cost involved e.g. cost of foundation seed, certification fees, cost to remove off-type plants, seed grading, packaging of seed, attaching tag, sealing and storing of seeds. During 2014-2015, minimum support price of one quintal of wheat was Rs. 1450. But certified seed of wheat was sold at a price of Rs. 2000-2500 per quintal. This way enterprise of seed production of certified and hybrid seed is very profitable.

There is also a fear of loss in this business also, as in other businesses. Some times the seed remains unsold and it can fail in laboratory test also. But the possibility of unsold seed is very less because already there is huge demand of seed in the market, which is not being fulfilled. So, this business is very profitable.

Question 2.
What do you mean by certified seed? Write three features of certified seeds.
Answer:
See in the above questions.

Question 3.
Which four parameters are examined in the seed test laboratory while examining seeds?
Answer:
By testing the seed in the laboratory we can check the standards. These standards are like:

• seed germination
• physical purity of seed.
• a number of diseased seeds
• number of seeds of weeds in the seeds, seeds of other crops.
• moisture percent in the seed.

Punjab State Board PSEB 10th Class Agriculture Book Solutions Chapter 8 Agro Based Industries Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Agriculture Chapter 8 Agro Based Industries

Agriculture Guide for Class 10 PSEB Agro Based Industries Textbook Questions and Answers

(A) Answer in one-two words:

Question 1.
Which crops can be dried and powdered at domestic level?
Answer:
Turmeric, Chillies etc.

Question 2.
From where the training on agro based industries can be obtained?
Answer:
Punjab Agriculture University, Ludhiana, Krishi Vigyan Kendras.

Question 3.
Name any two machines installed in agro processing complex.
Answer:
Mini rice mill, small flour mill, grinder, oil expeller, cotton ginning machine.

Question 4.
List the items in which mentha oil is used. What are the uses of peppermint (Mentha) oil?
Answer:
Medicines, perfumes, cosmetics etc.

Question 5.
How much Jaggery can be made from one quintal of sugarcane?
Answer:
10-12 kg.

Question 6.
What is the percentage of post-harvest losses in grains?
Answer:
10%.

Question 7.
What is the pre requisite for starting any agro based industry?
Answer:
Basic training.

Question 8.
How much powder can be made from one quintal of raw turmeric? Or How much turmeric powder can be produced during processing from 100 kg raw turmeric?
Answer:
15-20 kg.

Question 9.
How water and oil are separated during mentha processing?
Answer:
With the help of separator.

Question 10.
Name any two rural agro-based industries.
Answer:
Turmeric processing plant, Mentha procesing unit, Juggery manufacturing.

(B) Answer in one-two sentences:

Question 1.
What type of agro based industry can be set at cooperative level?
Answer:
A huge investment is (nearly 30 lakhs Rupees) is needed to set up dehydration and freezing plant for the processing of fruits and vegetables. Such units can be established at cooperative level and initial investment at individual level is reduced to large extent.

Question 2.
Why post harvest loss is taking place in our country?
Answer:
There is lack of sources for processing and storage, therefore post harvest losses are taking place.

Question 3.
What should be done to reduce the post harvest losses?
Answer:
We should process the agriculture produce to stop the damage of grains.

Question 4.
How agro based industries can be helpful in enhancing income of the fanners?
Answer:
Farmers can get more income by processing and selling of the agricultural produce at small scale. Farmer can also increase his income by adopting the occupations like – poultry farming, dairy farming etc.

Question 5.
Discuss the method for processing mentha.
Answer:
For extracting oil from mentha, mentha processing plant is established. Mentha crop is dried in open sun to reduce the moisture content. It is taken in an,air tight tanks in which steam is passed at pressure. Oil gets heated up and gets mixed with steam. Oil and steam mixture is removed from the tank and is cooled down quickly and oil and water are collected in another tank. This tank is known as separator. Oil is lighter than water and floats on the surface of water. It is decantated and collecte in plastic containers which are then sealed.

Question 6.
Describe the machine developed by PAU, Ludhiana for processing of turmeric.
Answer:
Punjab Agricultural University has developed a machine which is used for washing and polishing of turmeric. This machine can wash 2.5 -3.0 quintal turmeric in an hour and then can polish it also.

Question 7.
What are the technical operations related with jaggery manufacturing?
Answer:
Sugarcane is crushed using cane crusher. Juice so obtained is heated and concentrated to get jaggery.

Question 8.
Discuss any three machines used in agro processing complexes.
Answer:
Agro processing complexes can have machines like minirice mill, oil expel’ler, cotton gining machine etc. which are used to process paddy, oil seeds, cotton etc.

Question 9.
Why can’t the freezing plants for fruits and vegetables be installed at farmers’ level?
Answer:
A huge investment nearly Rs. 30 lakh is required to set up this unit. Therefore, it cannot be established at farmer’s level.

Question 10.
Which agricultural produces can be used at home after drying? Or Write the name of four agricultural products which are used dried at domestic travel.
Answer:
Fenugreek, corriander, mint, chillies etc. can be used at homes after drying.

(C) Answer in five-six sentences:

Question 1.
Discuss the advantages of setting up of agro processing complexes in Punjab.
Answer:
Generally, there is damage of 10% grains after harvesting and in case of fruits and vegetables this damage and loss is upto 30 – 40%. If processing units are established at village level then such losses can be minimized. Farmers can get more income. Unemployed youth can get work and we can get fresh and high quality eatables. Due to availability of employment and earning, the migration towards cities is also reduced.

Question 2.
What type of machinery can be installed in a small agro processing complex and which crops will be processed?
Answer:
A small agro processing complex can have following machines.

• mini rice mill
• oil expeller
• small flour mill
• grinder
• pulse cleaner and grader
• cotton ginning machine
• small feed mill
• mini dal mill

These machines are used for processing pulses, cereals, oil seeds, spices, paddy, cotton etc. .

Question 3.
What should be done to stop the migration of people from rural to urban areas?
Answer:
People migrate towards cities due to non availability of employment and income per family is also not up to the mark instead it is very low. If more opportunities are made available and sources of income are also generated then this will help in stopping the migration towards the cities. Therefore encouragement should be given to agriculture based enterprises.

Youth in rural areas can set their own small processing units. Some other agriculture based enterprises like dairy farming, fish farming, poultry farming, mushroom cultivation, honey production, bee keeping etc. can be adopted. By self-marketing of the processed products, one can get more returns.

Question 4.
What should be the policy for capital intensive agro processing industry?
Answer:
There are some agro processing plants which have very high initial cost. For example, the cost to establish dehydration and freezing plant for fruits and vegetables is nearly Rs. 30 lakh. Such a plant cannot be set up. at an individual level. Such a unit should be established at cooperative level by group of farmers. This way one plant can be used by various farmers and they can process their produce and can market them.

Question 5.
Discuss the various operations involved in turmeric processing. Or How turmeric powder is prepared from raw tarmeric?
Answer:
For processing, all the turmeric, rhizomes are washed properly to remove soil sticking to it etc. For this purpose P.A.U. has developed a machine which can wash and polish turmeric. This machine can wash and polish simultaneously nearly 2.5 – 3.0 quintal turmeric per hour. After this step (i.e. washing etc.) turmeric is boiled so that fingers become soft and their colour becomes uniform.

If boiling is done in open container it takes an hour but if boiled in pressure cooker it takes 20 minutes. After boiling, turmeric fingers are dried in sun so that moisture content is less than 10%. It takes nearly 15 days if strong sunlight is available. Now top layer of turmeric is removed by polishing. Then it is grounded in the grinder (hammer mill). This way 100 kg fresh turmeric gives 15-20 kg. powdered turmeric.

PSEB 10th Class Agriculture Guide Agro Based Industries Important Questions and Answers

Multiple Choice Questions

Question 1.
……………… kg turmeric powder can be obtained from 100 kg of fresh turmeric.
(a) 25-30
(b) 15-20
(c) 5-10
(d) 45-50.
Answer:
(b) 15-20

Question 2.
……………..kg Gud can be prepared from one quintal sugarcane.
(a) 21-22
(b) 30-35
(c) 10-12
(d) 18-20.
Answer:
(c) 10-12

Question 3.
After harvesting, there is nearly …………. loss in Crops.
(a) 5%
(b) 10%
(c) 20%
(d) 50%.
Answer:
(b) 10%

Question 4.
Mentha oil is used in
(a) medicines
(b) perfumes
(c) cosmetics
(d) All.
Answer:
(d) All.

Question 5.
After harvesting loss in fruits and vegetables in:
(a) 15-20%
(b) 20-30%
(c) 30-40%
(d) 10-15%.
Answer:
(c) 30-40%

Question 6.
How much jaggery (Gud) can be prepared from 100 kg sugarcane?
(a) 10-12 kg
(b) 40-45 kg
(c) 60-70 kg
(d) 30-35 kg.
Answer:
(a) 10-12 kg

Question 7.
What name of Punjabi magazine published by Punjab Agricultural university every month?
(a) Changi kheti
(b) Modem kheti
(c) Kheti niya
(d) Krishi jagran.
Answer:
(a) Changi kheti

Question 8.
From which crop is raw material for textile industry obtained?
(a) wheat
(b) cotton
(c) sugarcane
(d) mustard.
Answer:
(b) cotton

Question 9.
Which machine is used for oil extraction from oil seeds?
(a) Oil expeller
(b) Flour mill
(c) Seed grader
(d) Grinder.
Answer:
(a) Oil expeller

Question 10.
Which machine is used for cleaning of seed
(a) Oil expeller
(b) Flour mill
(c) Seed grader
(d) Grinder.
Answer:
(c) Seed grader

True False:

1. Post harvest losses in grains are approximately 10%.
Answer:
True

2. Mentha is a weed.
Answer:
False

3. We can get 15-20 kg of turmeric powder from 100 kg of fresh turmeric.
Answer:
True

4. We can get 30-40 kg of Jaggery from one quintal sugarcane.
Answer:
False

Fill in the blanks:

1. Post harvest losses in fruits and vegetables is …………….. .
Answer:
30-40 %

2. ……………. is used to dry vegetables.
Answer:
Solar dryer

3. During Mentha processing, oil and water are separated with the help of …………. .
Answer:
Separator

4. Mentha processing plant is used to extract oil from ……………. crop.
Answer:
Mentha.

Very Short Answer Type Questions

Question 1.
Give one reason of unemployment.
Answer:
Limited number of jobs.

Question 2.
How much damage/loss occur to the vegetables and fruits after harvesting?
Answer:
30 – 40%.

Question 3.
How much is the cost for setting up of agro-processing complexes?
Answer:
5 to 20 lakh Rupees.

Question 4.
How many days are required to dry turmeric fingers after boiling?
Answer:
In strong sunlight 15 days.

Question 5.
What is use of turmeric?
Answer:
Medicines, cosmetics and as dye in cotton clothes.

Question 6.
What is used for drying vegetables?
Answer:
Solar drier.

Question 7.
Name monthly magazine related to agriculture?
Answer:
‘Changi Kheti’.

Question 8.
How many Krishi Vigyan Kendras are under P.A.U.?
Answer:
17.

Question 9.
Write the name of four agricultural related co-occupations.
Answer:
Cattle rearing (Cows, goats, sheep etc), Poultry fanning, Honey bee rearing, fish rearing, Dairy farm, etc.

Question 10.
What is the use of flour mill (atta chakki)?
Answer:
Used to grind wheat, maize seeds to get flour.

Short Answer Type Questions

Question 1.
Is there any financial help available by government or other organisation for establishing agriculture based enterprises?
Answer:
Government as well as many other organisations provide financial help and training to establish agriculture based occupations.

Question 2.
What is the cost of establishment of agro-processing unit and how much is the income from this unit?
Answer:
Cost for setting up these machines is from Rs. 5 to 20 lakh and one can get an income of Rs. 10 thousand to 50 thousand per month.

Question 3.
Give uses of turmeric (in food).
Answer:
Turmeric is used to prepare various vegetables curries, to give taste, colour and flavour to the food items and it is also used for preparing food and chatnies at large scale.

Question 4.
Which things can be dried in solar drier?
Answer:
Fenugreek leaves, corriander, chilli, garlic etc. and some medicinal plants can be dried.

Question 5.
Write down the names of four agro based industries which can be started at the village level.
Answer:
Do it yourself.

Long Answer Type Questions

Question 1.
Write about processing of turmeric.
Answer:
Answer yourself.

Question 2.
Write about processing of mentha?
Answer:
Answer yourself.

Question 3.
Write the name of any ten agriculture based enterprises.
Answer:

• Poultry farming
• Dairy farming
• Honey production
• Mushroom cultivation
• Fish farming
• Jaggery manufacturing
• Drying of vegetables and their packaging
• Agro-processing complex
• Turmeric processing unit
• Mentha processing plant.

Punjab State Board PSEB 10th Class Science Book Solutions Chapter 1 Chemical Reactions and Equations Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations

PSEB 10th Class Science Guide Chemical Reactions and Equations Textbook Questions and Answers

Question 1.
Which of the statements about the reaction below are incorrect?
2PbO(s) + C(s) → 2Pb(s) + CO₂(g)
(a) Lead is getting reduced.
(b) Carbon dioxide is getting oxidised.
(c) Carbon is getting oxidised.
(d) Lead oxide is being reduced.
(i) (a) and (b)
(ii) (a) and (c)
(iii) (a), (b) and (c)
(iv) all.
Answer
(i) (a) and (b)

Question 2.
Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
The above reaction is an example of a
(a) combination reaction.
(b) double displacement reaction.
(c) decomposition reaction.
(d) displacement reaction.
Answer:
(d) displacement reaction.

Question 3.
What happens when dilute hydrochloric acid is added to iron filings?
Tick the correct answer.
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Answer:
(a) Hydrogen gas and iron chloride are produced.

Question 4.
What is a balanced chemical equation? Why should chemical equations be balanced?
Answer:
Balanced chemical equation. It is a chemical equation in which number of atoms of each element are equal on both sides of the equation.

The chemical equation should be balanced because law of conservation of mass holds good i.e., the total mass of the reactants must be equal to the total mass of the products.

Question 5.
Translate the following statements into chemical equations and then balance them :
(a) Hydrogen gas combines with nitrogen to form ammonia.
Answer:
3H₂ (g) + N₂ → 2NH₃ (g)

(b) Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
Answer:
2H₂S (g) + 3O₂ (g) → 2H₂O (l) + 2SO₂ (g)

(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
Answer:
3BaCl₂ + A12(SO₄)₃ → 2AlCl₃ (aq) + 3BaSO₄ (s)↓

(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
Answer:
2K (s) + 2H₂O (l) → 2KOH (aq) + H₂ (g)

Question 6.
Balance the following chemical equations :
(a) HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + H₂O
Answer:
2HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + 2H₂O

(b) NaOH + H₂SO4 → Na₂SO₄ + H₂O
Answer:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

(c) NaCl + AgNO₃ → AgCl + NaNO₃
Answer:
NaCl + AgNO₃ → AgCl + NaNO₃

(d) BaCl₂ + H₂SO₄ → BaSO₄ + HCl
Answer:
BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl

Question 7.
Write the balanced chemical equations for the following reactions :
(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
Answer:
Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

(b) Zinc + Silver nitrate → Zinc nitrate + Silver.
Answer:
Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag

(c) Aluminium + Copper chloride → Aluminium chloride + Copper.
Answer:
2Al + 3CuCl₂ → 2AlCl₃ + 3Cu

(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride.
Answer:
BaCl₂ + K₂SO₄ → BaSO₄ + 2KCl

Question 8.
Write the balanced chemical equation for the following reaction and identify the type of reaction in each case.
(a) Potassium bromide (aq) + Barium iodide (aq) → Potassium iodide (aq) + Barium bromide (s)
Answer:
2KBr (aq) + Bal₂ (aq) → 2KI (aq) + BaBr₂ (aq) — Double displacement reaction

(b) Zinc carbonate (s) → Zinc oxide (s) + Carbon dioxide (g)
Answer:
ZnCO₃ (s) → ZnO (s) + CO₂ (g) — Decomposition reaction

(c) Hydrogen (g) + Chlorine (g) → Hydrogen chloride (g)
Answer:
H₂(g) + Cl₂ (g) → 2HCl(g) — Combination reaction

(d) Magnesium (s) + Hydrochloric acid (aq) → Magnesium chloride (aq) + Hydrogen (g)
Answer:(a)
Mg(s) + 2HCl(aq) → MgCl₂ (aq) + H₂ (g) — Displacement reaction

Question 9.
What is meant by exothermic and endothermic reactions? Give examples.
Or
Differentiate between exothermic and endothermic reactions.
Answer:
Exothermic reaction. It is a chemical reaction in which heat energy is given out.
e.g. C (s) + O₂ (g) → CO₂ + Heat energy
NaOH (aq) + HCl (aq) → NaCl (aq) + H₂O (l) + Heat energy

Endothermic reaction : It is a chemical reaction in which heat energy is absorbed,
e.g. N₂ (g) + O₂ (g) → 2NO (g) — Heat energy
C (S) + H₂O (g) → CO + H₂ (g) — Heat energy.

Question 10.
Why is respiration considered as an exothermic reaction? Explain.
Answer:
During respiration oxidation of glucose occurs which produces heat energy.

Question 11.
Why are decomposition reactions called opposite of combination reactions? Write equations for these reactions.
Answer:
During decomposition a single substance breaks down into two or more substances which is just the reverse of combination reaction.

Examples for decomposition reactions are :

Question 12.
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
Answer:

Here electrical energy is supplied to bring about the reaction.

Question 13.
What is the difference between the displacement and double displacement reactions? Write equations for these reactions.
Answer:
Displacement reaction: In this reaction a more active element displaces less active element from solution of its compound. Examples:
Fe (s) + CuSO₄ (aq) → FeSO₄ (aq) + Cu (s) ↓
Zn (s) + CuSO₄ (aq) → ZnSO₄ (aq) + Cu (s) ↓

Double displacement reaction: The reaction in which there is an exchange of ions between two reactants is called a double displacement reaction.
AgNO₃ (aq) + NaCl (aq) AgCl (s) ↓ + NaNO₃ (aq)
BaCl₂ (aq) + Na₂SO₄ (aq) BaSO₄ (s) ↓ + 2NaCl (aq)

Question 14.
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
Answer:
Cu (s) + 2AgNO₃ (aq) → Cu(NO₃)₂ (aq) + 2Ag ↓

Question 15.
What do you mean by precipitation reaction? Explain by giving examples.
Answer:
Precipitation reaction. A reaction in which an insoluble product or precipitate is produced is called precipitation reaction.
AgNO₃ (aq) + NaCl (aq) → AgCl (s) ↓ + NaNO₃ (aq)
BaCl₂ (aq) + Na2SO₄ (aq) → BaSO₄ (s) ↓ + 2NaCl (aq)

Question 16.
Explain the following in terms of gain or loss of oxygen with two examples each :
(a) Oxidation (b) Reduction.
Answer:
(a) Oxidation: A chemical reaction in which a substance gains oxygen or loses hydrogen is called oxidation.
Examples

(b) Reduction: A chemical reaction in which a substance loses oxygen or gains hydrogen is called reduction.

Question 17.
A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black coloured compound formed.
Answer:
The element X is copper.

Therefore the black coloured compound formed is copper (II) oxide (CuO).

Question 18.
Why do we apply paint on iron articles?
Answer:
The iron articles can be protected from rusting by applying paint on them so that the iron surface does not come in contact with air (or oxygen) and moisture which causes rusting.

Question 19.
Oil and fat containing food items are flushed with nitrogen. Why?
Answer:
This is because food items are prevented from oxidation by oxygen or air.

Question 20.
Explain the following terms with one example each :
(a) Corrosion
Answer:
Corrosion: The slow eating up of metals by the action of air and moisture on their surfaces is called corrosion. For example, iron undergoes corrosion or rusting in the presence of moist air.

(b) Rancidity.
Answer:
Rancidity: When fats and oils or food containing oils and fats get oxidised with air or oxygen, their smells and tastes change, This process is called rancidity. For example, the packet containing potato chips is flushed with nitrogen gas to avoid rancidity.

Science Guide for Class 10 PSEB Chemical Reactions and Equations InText Questions and Answers

Question 1.
Why should a magnesium ribbon be cleaned before burning in air?
Answer:
Magnesium ribbon should be cleaned before burning to remove the protective layer of basic magnesium carbonate from its surface.

Question 2.
Write the balanced equation for the following chemical reactions.
(i) Hydrogen + Chlorine → Hydrogen chloride
Answer:
H₂ + Cl₂ → 2HCl

(ii) Barium chloride + Aluminium Sulphate → Barium Sulphate + Aluminium Chloride
Answer:
3BaCl₂ + Al₂(SO₄)₃ → 3BaSO₄ + 2AlCl₃

(iii) Sodium + Water → Sodium hydroxide + Hydrogen
Answer:
2Na + 2H₂O → 2NaOH + H₂

Question 3.
Write a balanced chemical equation with state symbols for the following reactions.
(i) Solutions of barium chloride and sodium sulphate in water react to give insoluble sulphate and the solution of sodium chloride.
Answer:
BaCl₂(aq) + Na₂SO4(aq) → BaSO₄(s) + 2NaCl(aq)

(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride and water.
Answer:
NaOH (aq) + HCl (aq) → NaCl (aq) + H₂O (l)

Question 4.
A solution of substance “X’ is used for white washing.
(i) Name the substance X’and write its formula.
Answer:
X is calcium oxide (quick lime) and its formula is CaO.

(ii) Write the reaction of the substance X named in (i) above with water.
Answer:
CaO (s) + H₂O(l) → Ca(OH)₂ (aq)

Question 5.
Why is the amount of gas collected in one of the test tubes in activity 1.7 double of the amount collected in the other? Name this gas.
Answer:
When electric current is passed through acidulated water, the reaction taking place is

Therefore hydrogen and oxygen produced are in the ratio 2 : 1 by volume. Hence volume of gas collected in one test tube is double the volume of gas collected in the other tube and this gas is hydrogen.

Question 6.
Why does the colour of copper sulphate solution change, when an iron nail is dipped in it?
Answer:
This is because iron displaces copper from copper sulphate solution.
Therefore, the concentration of copper sulphate solution decreases and blue colour of solution gradually fades away.

The concentration of copper sulphate solution decreases as ferrous sulphate is produced.

Question 7.
Give an example of a double displacement reaction other than the one given in the activity 1.10 given in textbook
Answer:
NaCl (aq) + AgNO₃(ag) → NaNO₃(aq) +AgCl(s) ↓

Question 8.
Identify the substances that are oxidised and the substances that are reduced in the following reactions :
(i) 4Na(s) + O₂(g) → 2Na₂O (s)
(ii) CuO(s) + H₂(g) → Cu(s) + H₂O(l)
Answer: