Question

Which of the following are decomposition reactions?

Answer 1

The 2 decomposition reactions are:

B. $K_{2}$$CO_{3}$ (s) --> $K_{2} O$ (s) + $CO_{2}$ (g)

C. $2SO_{3}$ (g) --> $2SO_{2}$ (g) + $O_{2}$ (g)

Explanation:

Step 1:

A decomposition reaction is one in which a single compound breaks down into two or more products.

Step 2:

Let us examine each reaction if it satisfies the above rule.

A. 2 LiOH +  $CO_{2}$ ---> $Li_{2} CO_{3}$ + $H_{2} O$

In this reaction we have 2 reactants giving 2 products. Hence this is not a decomposition reaction.

B. $K_{2} CO_{3}$ ---> $K_{2} O$ + $CO_{2}$

In this reaction a single reactant potassium carbonate gives rise to 2 products Potassium Oxide and carbon-di-oxide. Hence this is a decomposition reaction

C. $2SO_{3}$ ---> $2SO_{2}$ + $O_{2}$

In this reaction a single reactant sulfur tri-oxide gives rise to 2 products sulfur di-oxide and oxygen. Hence this is a decomposition reaction.

D. $2Na$ + $Cl_{2}$ ---> $2NaCl_{}$

In this reaction 2 reactants sodium and chlorine gives rise to a single product sodium chloride. Hence this is not a decomposition reaction.

Step 3:

Answer:

The 2 decomposition reactions are:

B. $K_{2} CO_{3}$ (s) ---> $K_{2}O$ (s) + $CO_{2}$ (g)

C. $2SO_{3}$ ---> $2SO_{2}$ + $O_{2}$