MCQs on Decomposition Reaction

MCQs on Decomposition Reaction

1. CO₂ obtained by the complete decomposition of 20 g CaCO₃ at STP is

(a) 4.48 l

(b) 2.24 l

(c) 44.8 l

(d) 48.4 l

Answer: (a)

2. Decomposition of hydrogen peroxide to give H₂O + O₂ is an example of

(a) reduction

(b) oxidation

(c) both (a) and (b)

(d) none of the above

Answer: (c)

3. The reaction 2Pb(NO₃)₂ → 2PbO + 4NO₂ + O₂ is a type of _______reaction.

(a) displacement

(b) double decomposition

(c) decomposition

(d) none of the above

Answer: (c)

4. On passing current to an acidified water we get hydrogen and oxygen. This is a type of

(a) oxidation reaction

(b) thermal decomposition

(c) electrolysis

(d) none of the above

Answer: (c)

5. The correct expression for decomposition of silver chloride to silver and chlorine is

(a) AgCl_2(s) → Ag_(s) + 2Cl_(g)

(b) 2AgCl_(s)→ 2Ag_(s) + Cl_2(g)

(c) AgCl_2(s) → Ag_(s) + Cl_2(g)

(d) AgCl_(s) → Ag_(s) + Cl_(g)

Answer: (b)

6. A reaction where two compounds exchange their atoms to form new compounds

(a) decomposition

(b) double displacement

(c) displacement

(d) synthesis

Answer: (b)

7. The decomposition of silver chloride occurs by

(a) heat

(b) sunlight

(c) water

(d) electricity

Answer: (b)

8. How many moles of sodium carbonate is formed on decomposition of 0.2 moles of sodium bicarbonate?

(a) 0.1

(b) 0.2

(c) 0.05

(d) 0.025

Answer: (a)

9. Find out the volume of CO₂ liberated after heating 9.85 g of BaCO₃ at STP.

(a) 2.06 l

(b) 2.12 l

(c) 1.12 l

(d) 4.84 l

Answer: (c)

10. Ferrous sulphate on heating gives reddish-brown residue of ferric oxide. This is due to

(a) decomposition

(b) displacement

(c) combination

(d) none of the above

Answer: (a)