Chemical reactions and equations MCQ

Chemical reactions and equations MCQ/objective questions Class 10 Science Chapter 1

1. Magnesium ribbon is cleaned before burning. Why?

A. It absorbs moisture from the atmosphere which interferes with burning.

B. It’s outer layer form oxides which interfere with burning.

C. Dust from the atmosphere prevents its burning.

D. All of the above

Answer

1(B)

2. Balanced equation of  Fe + H₂O ———–> Fe₃O₄ + H₂ is

A. Fe + 4H₂O ———–> Fe₃O₄ + H₂

B. Fe + 4H₂O ———–> Fe₃O₄ + 4H₂

C. 3Fe + 4H₂O ———–> Fe₃O₄ + 4H₂

D. 3Fe(s) + 4H₂O(l) ———–> Fe₃O₄(s) + 4H₂(g)

Answer

2(D)

3. What is the formula for quick lime. What does it form when put into water.

A. CaO, CaCO₃

B. CaO, Ca(OH)₂

C. Ca(OH)₂, CaCO₃

D. None

Answer

3(B)

4. A compound used for whitewashing is

A. Quick lime

B. Slaked Lime

C. Blue vitriol

D. Limestone

Answer

4(B)

5. Electrolysis of water is

A. Combination reaction

B. Decomposition reaction

C. Displacement reaction

D. None

Answer

5(B)

6. Example of displacement reaction is

A. Fe(s) + CuSO₄(aq)  ——>  FeSO₄(aq) + Cu(s)

B. C(s) + O₂(g)  ——–> CO₂(g)

Sunlight

C. AgCl(s)  ———> 2Ag(s) + Cl₂(g)

D. None

Answer

 6(A)

7. Lead nitrate Pb(NO₃)₂ on heating forms Lead oxide (PbO) solid and Nitrogen dioxide gas. What are the color of lead oxide and nitrogen dioxide?

A. White, Colourless

B. White, Brown

C. Yellow, Brown

D. Yellow, Colourless

Answer

 7(C)

8. Silver chloride on exposure to sunlight decomposes into silver and chlorine gas. This property is used in

A. Heat production as enormous energy is released.

B. Silver extraction as the earth contains silver mainly in silver chloride form.

C. Photography as formed grey silver forms an image imprint.

D. None

Answer

 8(C)

9. Quick lime is used in whitewashing because

A. It is cheap

B. It forms slaked lime with water which has a nice color.

C. It forms slaked lime with water which reacts with atmospheric carbon dioxide to form limestone.

D. None

Answer

9(C)

10. Example of a double displacement reaction will be

A. Metal with a salt

B. Metal with an acid

C. Metal with metal

D.  Salt with a salt

Answer

10(D)

11. A reaction of hydrogen with oxygen to form water is a

A. Endothermic reaction

B. Exothermic reaction

C. Decomposition reaction

D. Reaction not feasible

Answer

11(B)

12. Ferrous sulfate solution is green while ferric oxide formed by its decomposition is

A. Red

B. White

C. Brown

D. Yellow

Answer

12(C)

13. Corrosion or rusting of iron metal is

A. Oxidation of iron

B. Reduction of iron

C. Displacement of iron

D. None

Answer

1(B), 2(D), 3(B), 4(B), 5(B), 6(A), 7(C), 8(C), 9(C), 10(D), 11(B), 12(C), 13(C), 14(B), 15(C),16(B), 17(D), 18(B)

14. Rancidity of fat or oil is:

A. Degradation by the microorganism

B. Oxidation of fat

C. Reduction of fat

D. None

Answer

14(B)

15. To facilitate the electrolysis of water we add a few drops of acids like sulfuric acid or salts like NaCl. Because:

A. It acts as a catalyst

B. It prevents the decomposition of electrodes used.

C. It increases the electrical conductivity of water.

D. None

Answer

15(C

16. Food manufacture pack fried foods with which gas to prevent oxidation of fat?

A. Oxygen

B. Nitrogen

C. Any of the above

D. None

Answer

16(B)

17. The oxidation reaction is:

A. Addition of an oxygen atom

B. Removal of the hydrogen atom

C. Loss of electron

D. All

Answer

17(D)

18. The blue flame in the below image represents the burning of which metal?

A. Iron

B. Copper

C. Sodium

D. All metal burn to give a blue flame.

Answer

18(B)

Answers to MCQ’s: 1(B), 2(D), 3(B), 4(B), 5(B), 6(A), 7(C), 8(C), 9(C), 10(D), 11(B), 12(C), 13(C), 14(B), 15(C),16(B), 17(D), 18(B).

Next: Solved questions from Chemical Reactions and Equations.

See also:

Model questions for chapter 1.

 

Chemical reactions and equations MCQ/objective questions Class 10 Science Chapter 1

 

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Ncert class 10 science chapter 1 Chemical Reaction and Equations MCQ PDF

 

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