Chemical Reactions and Equations MCQ | Class 10 | Science | Chapter-1 | 2024

Last updated on July 14th, 2024 at 05:38 pm

Chemical Reactions and Equations MCQ

Chemical reaction is a process in which the substances (called the reactants) combine to form specific products.

Below are some of the very important NCERT Chemical Reactions and Equations MCQ Class 10 Science Chapter 1 with answers. These Chemical Reactions and Equations MCQ have been prepared by expert teachers and subject experts based on the latest syllabus and pattern of CBSE Term 1 examination.

We have given these Chemical Reactions and Equations MCQ Class 10 Science Questions with Answers to help students understand the concept.

MCQ Questions for Class 10 Science are very important for the latest CBSE Term 1 and Term 2 pattern. These MCQs are very important for students who want to score high in CBSE Board, NEET and JEE exam. 

We have put together these NCERT Chemical Reactions and Equations MCQ for Class 10 Science Chapter 1 with Answers for the practice on a regular basis to score high in exams. Refer to these MCQs Questions with Answers here along with a detailed explanation.

Chemical Reactions and Equations MCQ 1-25

1 . Which of the following reactions is an exothermic reaction?

1. Burning of coal.
2. Decomposition of vegetable matter into compost.
3. Process of respiration
4. Decomposition of calcium carbonate to form quicklime and carbon dioxide

2. Buming of the candle is a change

1. Physical   
2. Chemical
3. Both 1 and 2 
4. None of them

3. Zn + HCl → ZnCl₂ + _______

1. H²
2. Cl²
3. Zn   
4. None of these

4. Which among the following statement(s) is (are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to

(I) The formation of silver by decomposition of silver chloride.

(II) Sublimation of silver chloride.

(III) Decomposition of chlorine gas from silver chloride.

(IV) Oxidation of silver chloride.

1. (I) only
2. (I) and (III) only
3. (II) and (III) only
4. (IV) only

5. The reaction which decomposes after the supply of heat is called

1. Thermal decomposition
2. Combination reaction
3. Redox reaction
4. Displacement reaction

6. In a double displacement reaction such as the reaction between sodium sulphate solution and barium chloride solution

(I) exchange of atoms takes place.

(II) exchange of ions takes place.

(III) a precipitate is produced.

(iv) an insoluble salt is produced.

1. (II) & (IV) only
2. (I) & (III) only
3. (II) only
4. (II), (III) and (IV) only

7. Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is

1. 1:1
2. 2:1
3. 4:1
4. 1:2

8. What is the colour of the ash formed when a magnesium ribbon is burnt in the air?

1. White
2. Black
3. Yellow
4. Pink

9. What is the name of the process where fatty foods become rancid?

1. Corrosion
2. Oxidation 
3. Reduction
4. Hydrogenation

10. In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

1. 2H₂ (l) + O₂ (l) → 2H₂O (g)
2. 2H₂ (g) + O₂(l) → 2H₂O (l)
3. 2H₂ (g) + O₂(g) → 2H₂O (l)
4. 2H₂ (g) + O₂(g) → 2H₂O (g)

11. Which one of the following precipitates are formed when the carbon dioxide gas is passed through lime water?

1. Ca(OH)₂     
2. Ca(OH)₄
3. CaCO₃
4. CaCO₂

12. The following reaction is an example of a

4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)

(I) Displacement reaction

(II) Combination reaction

(III) Redox reaction 

(IV) Neutralisation reaction

1. (I) and (IV)
2. (II) and (III)
3. (I) and (III) 
4. (III) and (IV)

13. Which law should be kept in mind while we balance chemical equations?

1. Conservation of momentum
2. Conservation of mass
3. Conservation of energy   
4. Conservation of frequency

14. In which of the following, the identity of the initial substance remains unchanged?

1. Curdling of milk
2. Formation of crystals by process of crystallisation
3. Fermentation of grapes
4. Digestion of food

15. Which one of the following processes involves a chemical reaction?

1. Liquification of air
2. Heating copper wire in presence of air at high temperature
3. Keeping petrol in a china dish in the open  
4. Storing of oxygen gas under pressure in a gas cylinder

16. Shashank was asked to carry out a displacement reaction which would show the following  

(I) Formation of colourless solution

(II) Black deposits

The reactants he should use are

1. Fe(s) and Al₂(SO₄)₃ (aq)
2. Al(s) and FeSO₄ (aq)
3. Zn(s) and CuSO₄ (aq)
4. Fe(s) and ZnSO₄ (aq)

17. The oxidation reaction which produces heat and light is called

1. Endothermic
2. Photochemical   
3. Exothermic
4. Combustion

18.  Heating of ferrous sulphate is a type of

1. Decomposition reaction
2. Combination Reaction
3. Displacement reaction
4. All of the above

19. Fusion reaction is also known as

1. Chemical reaction
2. Elastic scattering
3. Thermonuclear reaction 
4. Photo nuclear reaction

20. To balance Al(OH)₃ + HNO₃ → Al(NO₃)₃ + H₂O, number of HNO₃ molecules required will be

1. 2     
2. 4   
3. 3     
4. 8

21. Which metal is displaced when lead is put in the solution of copper chloride?

1. Lead 
2. Copper  
3. Chlorine  
4. All of these

22. What does the symbol “↓” represent in a chemical reaction?

1. Gas released
2. Solid state
3. Precipitate formed     
4. Direction of reaction

23. Which of the following reaction is not feasible?

1. Aluminium + Copper sulphate
2. Zinc + Copper sulphate solution
3. Iron + Zinc sulphate solution
4. Copper + Zinc sulphate

24. A dilute ferrous sulphate solution was gradually added to the beaker containing acidified potassium permanganate solution. The light purple colour of the solution fades and finally disappears. 

Which of the following is the correct explanation for the observation?

1. KMnO₄ is an oxidising agent, it oxidises FeSO₄
2. FeSO₄ acts as an oxidising agent and oxidizes KMnO₄
3. The colour disappears due to dilution; no reaction is involved
4. KMnO₄ is an unstable compound and decomposes in presence of FeSO₄ to a colourless compound

25. Which of the following gases can be used for storage of fresh samples of an oil for a long time?

1. Carbon dioxide
2. Nitrogen     
3. Hydrogen   
4. Helium

MCQ Answers

1 . (4)

Decomposition of calcium carbonate to form quicklime and carbon dioxide is an exothermic reaction since this process absorbs heat from the atmosphere.

2. (3)

Burning of the candle is both physical and chemical change. Burning of the candle melts the wax and hence the physical state of wax has changed from solid to liquid. Again the wax combines with the atmospheric oxygen and changes to carbon dioxide, heat and light. Thus it is both a physical and a chemical change.

3. (1)

Zn + HCI → ZnCl₂ + H₂

4. (1)

Exposure of silver chloride to sunlight for a long duration turns silver chloride grey due to the photolysis reaction in which the decomposition of the silver chloride takes place in the presence of sunlight leading to the formation of silver.

5. (1)

A thermal decomposition reaction  occurs when heat is applied to a compound causing it to decompose (break down) into multiple different chemical substances. An example is when baking soda (sodium bicarbonate) is heated.

2NaHCO₃(s) → CO₂(g) + H₂O(g) + Na₂CO₃(s)

6. (4)

A double displacement reaction is the reaction in which the ions replace each other from their salt solution and these reactions can be accompanied by the formation of the precipitate or the formation of the insoluble salt.

7. (2)

The mole ratio of hydrogen and oxygen gases liberated during the electrolysis of water is 2:1. Since two atoms of hydrogen and one atom of oxygen are present in the water molecule respectively.

2H₂O → 2H₂ + O₂

8. (1)

When the magnesium ribbon is burned in the air it burns with the white dazzling flame leading to the formation of the white colour precipitate.

9. (2)

Fatty foods become rancid due to the process of Oxidation. Food turns rancid when the fats and oils within them get oxidised and the taste and smell of the food changes. It is produced by aerial oxidation of unsaturated fat present in foods and other products, marked by unpleasant odour or flavour.

10. (3)

Hydrogen and oxygen occurs in the gaseous state in nature whereas when they react and combine to forms water, water is in liquid form.

11. (3)

When CO₂ is passed through lime water, it turns milky due to formation of white precipitate of calcium carbonate.

12. (3)

This reaction is an example of and redox reaction since oxygen replaces hydrogen from the ammonia molecule leading to the formation of NO. Similarly O₂ is getting reduced in the reaction and ammonia getting oxidised thus the redox reaction takes place in this reaction. Therefore the above reaction is both the displacement and the redox reaction.

13. (2)

The law of conservation of mass states that “mass can neither be created nor destroyed.” So both the sides of the chemical reactions have to be balanced to ensure that this law is followed and thus the number of the reactant and the product molecules remains same on both side of the equation.

14. (2)

Formation of crystals by process of crystallisation is the reaction in which the original identity of the substance remains as such since on heating the crystals they can again be converted in the powder form and again on cooling they can recrystallize.

15. (2)

When copper or copper wire is heated in presence of air very slowly at high temperature, a layer of brown black copper oxide is formed which protects the copper from extensive corrosion. Thus due to the formation of this layer on the surface of the copper wire it is a chemical change.

16. (2)

Aluminium being higher in reactivity series displaces the iron in ferrous sulphate  solution.

When aluminium metal is added to ferrous sulphate (FeSO₄) solution, the green colour of ferrous sulphate solution disappears due to the formation of aluminium sulphate solution and greyish black iron gets deposited.

3FeSO₄(aq) (Green solution) + 2Al (s) → 2Fe(s) (Greyish Black solution) + Al₂(SO₄)₃(aq) (Colourless solution)

17. (4)

A combustion reaction is a kind of chemical reaction in which a reaction between any combustible substance and an oxidiser takes place in order to form an oxidised product accompanied by the evolution of heat and light during the reaction.

18. (1)

A decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances. Most decomposition reactions require an input of energy in the form of heat, light, or electricity.

19. (3)

Thermonuclear reaction, is the reaction in which the fusion of two light atomic nuclei into a single heavier nucleus takes place by the collision of the two interacting particles at extremely high temperatures, with the consequent release of a relatively large amount of energy.

20. (3)

Three molecules of HNO₃ are required to balance the given chemical reaction and to satisfy the law of conservation of mass.

Al(OH)₃ + 3HNO₃ → Al(NO₃)₃ + 3H₂O

21. (2)

Copper will be displaced from the solution since it is less reactive than lead and lead will displace copper from its salt solution because it is more reactive than copper.

22. (3)

The symbol “↓” represents the formation of the precipitate in a chemical reaction

23. (4)

Copper + Zinc sulphate is not the feasible reaction since zinc is more reactive than copper and copper cannot displace it from its salt solution as per the reactivity series of metals

24. (1)

Since Potassium permanganate (KMnO₄) is quite an unstable compound, it tends   to decompose in the presence of Ferrous sulphate (FeSO₄). This changes the colour of the solution from purple to colourless.

25. (4)

Helium can be used to store the fresh samples of an oil for a long time since it is an inert gas and will not react with the sample of the food keeping its quality intact as such.

Very Short Answer Question

1 . Why is the displacement reaction also known as a single displacement reaction?

2. Why is hydrogen included in the activity series of metals?

3. Why does gold and silver not corrode in moist?

4. Why is the silver bromide kept in coloured bottle?

5. Why do we paint iron articles?

6. State whether the following statement is true or false.

‘A chemical equation can be balanced easily by altering the formula of reactant or product’

7. Which reaction is used in photography?

8. Which chemical reaction is used for obtaining a metal from its oxide?

9. Which element is on the top of the activity series and which on the bottom?

10. Give two ways by which corrosion can be prevented.

Very Short Answer Question Answers

1 . In displacement reaction only one atom or ion is displaced, that is why it is also known as single displacement reaction.

2. Hydrogen is included in activity series of metals because like metals, hydrogen can also lose electrons to form positive ions.

3. Gold and silver lie very low in the activity series of metals. Thus, they have low reactivity and hence do not corrode in moist air.

4. Silver bromide is kept in coloured bottles because it decomposes in the presence of light, so as to prevent this decomposition, it is kept in coloured bottles.

5. Iron articles are painted to prevent them from rusting. When iron articles are painted, the contact of iron articles from moisture and air is cut off. Therefore, rusting is prevented.

6. False

7. Photo-decomposition of silver chloride is used in photography.

8.  Reduction reaction.

9. Potassium is on the top and gold is at the bottom.

10. (a) Painting (b) Electroplating (c) Galvanizing

Assertion and Reasoning MCQ

Codes

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true and but R is not a correct explanation of A

(c) A is true but R is false

(d) A is false, but R is true

1 . Assertion Chemical equations should be balanced. 

Reason As per the law of conservation of mass, mass can neither be created nor be destroyed.

2. Assertion Hydrogen peroxide is kept in coloured bottles.     

Reason Hydrogen peroxide is a moderately reactive metal that can react with light or heat slowly to produce water.

3. Assertion Silver bromide is kept in the coloured bottles.      

Reason Silver bromide is kept in coloured bottles because it decomposes in the presence of light.

4. Assertion Colour of copper sulphate solution changes when an iron nail is kept immersed in it.     

Reason The colour of copper sulphate solution changes when iron nail is kept immersed in it due to the decomposition reaction taking place between iron and copper leading to formation of iron sulphate.

5. Assertion Hydrogen is not included in the activity series of metals.     

Reason It is because it can lose electrons to form positive ions.

6. Assertion Copper vessels get covered with green coating in the rainy season.      

Reason It is because of the formation of copper carbonate

7. Assertion Gold and silver do not corrode in moist air.     

Reason It is because they have low reactivity.

8. Assertion Paint is applied on the iron articles.     

Reason To protect them from rain.

9. Assertion Photosynthesis is considered as an exothermic reaction.     

Reason Photosynthesis is an endothermic reaction because sunlight energy is absorbed by green plants during this process.

10. Assertion Silver articles become black after sometime when exposed to sunlight.     

Reason It is because silver reacts with carbonates present in the air.

Assertion and Reasoning MCQ Answers

1 . (a)

The chemical equations should be balanced because as per the law of conservation of mass “mass can neither be created nor be destroyed”. Therefore the number of atoms on both sides of the equations should be equal.

2. (c)

Hydrogen peroxide is a highly reactive metal that can react with light or heat to produce water it decomposes into water and oxygen in the presence of sunlight to prevent this reaction with light and heat it is stored in coloured bottles so that light cannot pass through it.

3. (a)

Silver Bromide is kept in coloured bottles because it decomposes in the presence of light so as to prevent is decomposition it is kept in coloured bottles.

4. (c)

The colour of copper sulphate solution changes when iron nail is kept immersed in it due to the displacement reaction taking place between iron and copper leading to formation of iron sulphate.

5. (d)

Hydrogen is included in activity series of metals because like metals hydrogen can also lose electrons to form positive ions.

6. (b)

Copper vessel is covered with green coating in rainy season due to attack of oxygen carbon dioxide in water vapours of the air on copper forming green coloured basic copper carbonate.

7. (a)

Gold and silver lie very low when the activity series of metals does they have low reactivity and hence do not corrode in moist air.

8. (c)

Iron articles are painted to prevent them from rusting.

9. (d)

Photosynthesis is an endothermic reaction because the sunlight energy is absorbed by green plants during this process.

10. (c)

Silver reacts with sulphur present in the air and form the layer of silver sulphide therefore silver articles get tarnished.

Case Study Based MCQ

1 . Read the passage carefully and answer any four questions.

Situations of daily life can be represented by equations in a few variables. In the same way, chemical reactions can be represented with the help of symbols of elements and formulae of the substances involved. 

This method of writing a reaction is known as a chemical equation. The substances which combine to react are known as reactants and new substances produced are known as products. 

An unbalanced chemical equation needs to be balanced which means that an equal number of atoms of different elements are present in the reactant as well as in the product side. 

Most importantly, the formulae of the compounds are not altered while balancing the equation.

(i) Chemical equations balancing is in accordance with

1. Law of constant proportions
2. Law of combining volumes 
3. Law of conservation of mass
4. Both 1 and 3

(ii) The chemical equation which is unbalanced is

1. 2NaHCO₃ → Na₂CO₃ + H₂O + CO₂ 
2. 2C₄H₁₀ + 12O₂ → 8CO₂ + 10H₂O
3. 2Al + 6H₂O → 2AI(OH)₃ + 3H₂
4. 4NH₃ + 5O₂ → 4NO + 6H₂O

(iii) In the given balanced equation, the coefficients a, b, c, d respectively are

a Mg₃N₂ + b H₂O → c Mg(OH)₂ + d NH₃

1. 1, 3, 3, 2   
2. 1, 6, 3, 2
3. 1, 2, 3, 2
4. 2, 3, 6, 2

(iv) Which of the following is not conveyed by a balanced chemical equation

1. If a particular reaction is practically feasible or not
2. Symbols and formulae of all the reactants
3. Number of atoms and molecules of the products formed   
4. The physical state of reactants and products

(v) Which of the following is true for an unbalanced chemical equation?

1. The number of atoms is more on the right side of the equation
2. The number of atoms is less on the left side of the equation
3. The number of atoms is equal on both sides of the equation
4. Both 1 and 2

2. Read the passage carefully and answer any four questions.

A decomposition reaction is opposite to a combination reaction. A single reactant breaks down to form two or more products in a decomposition reaction. 

Thermal decomposition reaction uses the energy in form of heat for decomposition reactants. Electrolytic decomposition reactions involve the use of electrical energy for the breakage of reactant molecules. Photolysis or Photochemical decomposition involves the use of light energy.

(i) Name the components of our diet, decomposition of which produces the amino acid

1. Starch
2. Protein
3. Carbohydrate 
4. Fat

(ii) Silver chloride (AgCl) when exposed to sunlight for a long duration turns grey. Consider the following statements

1. The formation of silver by decomposition of silver chloride 
2. Sublimation of silver chloride 
3. Decomposition of chlorine gas from silver chloride 
4. Oxidation of silver chloride

(iii) Which of the following is a decomposition reaction

1. NaOH + HCI → NaCI + H2O
2. NH₄CNO → H₂NCONH₂ 
3. 2KClO₃ → 2KCl + 3O₂
4. H₂ + I₂ → 2HI

(iv) 2Pb(NO₃)₂ → 2PbO + nA + O₂

1. 4NO
2. 4NO₂
3. 2PbNO₂
4. NO₂

(v) When electricity is passed through water what kind of the reaction take place

1. Thermal decomposition 
2. Electrolytic decomposition for 
3. Photochemical decomposition 
4. Displacement reaction

3. Read the following and answer any four questions.

Chemistry in automobile:

For an internal combustion engine to move a vehicle down the road, it must convert the energy stored in the fuel into mechanical energy to drive the wheels. 

In your car, the distributor and battery provide this starting energy by creating an electrical ‘spark’, which helps in combustion of fuels like gasoline. Below is the reaction depicting complete combustion of gasoline in full supply of air.

2C₈H₁₈ (l) + 25O₂ (g) → 16’X’

(i) Which of the following are the products obtained from the reaction mentioned in the above case?

(ii) Identify the types of chemical reaction occurring during the combustion of fuel.

1. Oxidation of endothermic reaction
2. Decomposition of exothermic reaction
3. Oxidation and exothermic reaction
4. Combination and endothermic reaction

(iii) On the basis of evolution/absorption of energy, which of the following processes are similar to combustion of fuel?

(I) Photosynthesis in plants

(II) Respiration in human body

(III) Decomposition of vegetable matter

(IV) Decomposition of ferrous sulphate

1. II and III
2. I and II
3. III and IV
4. II and I

(iv)  ‘A student while walking on the road observed that a cloud of black smoke bleached out from the exhaust stack of moving trucks on the road’. Choose the correct reason for the production of black smoke.

1. Limited supply of air leads to incomplete combustion of fuel
2. Rich supply of air leads to complete combustion of fuel
3. Rich supply of air leads to a combination reaction
4. Limited supply of air leads to complete combustion of fuel

(v)  ‘Although nitrogen is the most abundant gas in the atmosphere, it doesn’t take part in combustion’. Identify the correct reason for his statement.

1. Nitrogen is a reactive gas
2. Nitrogen is an inert gas
3. Nitrogen is an explosive gas
4. Only hydrocarbons can take part in combustion

4. Read the passage carefully and answer any four questions.

During a chemical reaction, it is possible that one element takes the place of another element in a compound. Such reactions are called displacement reactions. 

Precisely, an element that is high in the reactivity series, displaces an element that is lower in the reactivity series. 

In single displacement reactions, only one element displaces the other element from its compound. The displacement reaction between Iron (III) Oxide and powdered aluminium produces so much heat that the iron gets into its molten state.

(i) Copper displaces which of the following metals from its salt solution?

1. ZnSO₄
2. FeSO₄
3. AgNO₃
4. NiSO₄

(ii) Characteristic of the gas evolved during the reaction of zinc with dilute sulphuric acid is

1. Green in colour having a foul smell
2. Colourless, odourless and burns with a pop sound
3. Red in colour having a sweet smell
4. Colourless, pungent smelling and burns with a pop sound

(iii) A reddish brown residue is obtained when dry hydrogen is passed over a heated oxide of metal ‘m’. This residue could be

1. Lead
2. Silver
3. Copper
4. Zinc

(iv) Which among the following is a displacement reaction?

1. CaO +H₂O → Ca(OH)₂ 
2. MgCO₃ → Mg + CO₂
3. Mg + CuSO₄ → MgSO₄ + Cu
4. H₂ + Cl₂ → 2HCl

(v) Which is the correct observation for the reaction between granulated zinc and dilute HCl?

1. The reaction mixture turns milky
2. Greenish yellow gas is evolved
3. The colourless and odourless gas evolves with a pop sound
4. The surface of the metal turns shiny

5. Read the passage carefully and answer any four questions.

We all must have observed that newly bought iron, silver or copper articles appears  very shiny but with passage of time they get dull. This is due to the layer of metal oxide that develops on their surface. Metals react with atmospheric oxygen and produce metal oxides. In case of rusting of iron, the iron reacts with the oxygen present in air and moisture and develops rust.

Corrosion causes damage to car bodies, bridges, iron railings, ships and to all objects made of metals, especially those of iron. In case of rusting of copper, the metallic copper reacts with oxygen,  carbon dioxide and atmospheric moisture and develops a green coloured coating over copper.

(i) Give examples of corrosion.

(ii) What is the chemical formula of rust?

(iii) Name the chemical compounds that form green coating when copper reacts with oxygen, carbon dioxide and atmospheric moisture.

(iv) What is the nature of corrosion products?

6. Annie was happy to see her small house getting cleaned and whitewashed. She observed that the workers dissolved some pale white powdery material called quicklime into water (a vigorous reaction takes place while mixing) left it for some time and applied the white suspension obtained to the walls. At first the wall looked pale white and watery but in 2-3 days the walls became shiny bright white in colour. How can you describe what she observed through chemical equations?

7. A metal ‘X’ left in moist air for a longer time, loses its shiny brown surface and gains a green cost. Why has this happened? Name and give the chemical formula of the given coloured compound and identify the metal. List two ways to prevent this process.

8. Based on the table given below answer the following questions.

(i) Give the reaction involved in formation of silver from silver bromide.

(ii) Name the type of reaction involved in formation of ammonium chloride.

(iii) Name the type of reaction involved in formation of silver from silver bromide.

(iv) Name the type of reaction involved in formation of hydrogen from water

Case Study Based MCQ Answers

1 . (i) (3) (ii) (2) (iii) (2) (iv) (1) (v) (4)

2. (i) (2) (ii) (1) (ii) (3) (iv) (2) (v) (2)

3. (i) (4) (ii) (3) (iii) (1) (iv) (1) (v) (2)

4. (i) (3) (ii) (2) (iii) (3) (iv) (3) (v) (3)

5.

(i) Rusting of iron, silver getting tarnished and copper getting a green layer are examples of rusting.

(ii) Formula for rust is 2Fe₂O₃.H₂O

(iii) 2Cu + H₂O + CO₂ + O₂ → Cu(OH)₂ + CuCO₃

(iv) Corrosive products are basic in nature.

6. Quick lime is chemically known as calcium oxide. It reacts vigorously with water to produce slaked lime (calcium hydroxide), releasing a large amount of heat.

CaO + H₂O → Ca(OH)₂

The slaked lime after application to wall reacts slowly with carbon dioxide present in atmosphere, to give a thin layer of calcium carbonate on the walls after 2-3 days giving the walls a shiny bright white colour

Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

7. This has happened because of corrosion of metal on being exposed to moist air. Green coloured compound is basic copper carbonate. Its chemical formula is

The metal is Copper. Two ways to prevent corrosion are :

1. Painting and oiling.
2. Electroplating

8.

(i) The reaction involved in formation of silver from silver bromide is

2AgBr → 2Ag + Br

(ii) The formation of ammonium chloride from ammonia and chlorine is an example of combination reaction.

(iii) The formation of silver from silver bromide is an example of decomposition reaction.

(iv) The formation of hydrogen from water is an example of electrolysis reaction.

Final Words

From the above article, you have practiced Chemical Reactions and Equations MCQ of Class 10 Science Chapter 1. We hope that the above mentioned latest Chemical Reactions and Equations MCQ for Term 1 of Chapter 1 will surely help you in your exam.

If you have any doubts or queries regarding the Chemical Reactions and Equations MCQ with Answers of CBSE Class 10 Science, feel free to reach us and we will get back to you as early as possible.