Question

Write the balanced chemical equation for the following reaction and identify the type of reaction:
Zinc carbonate(s) → zinc oxide(s) + Carbon dioxide(g)

Answer 1

Zinc carbonate(s) → zinc oxide(s) + Carbon dioxide(g)

1. Balancing steps:
Step 1: Write unbalanced equation.

$\mathrm{ZnCO}{}_3\to \mathrm{ZnO}+\mathrm{CO}{}_2$

Step 2: Write down the number of atoms of each elements present on both reactant as well as product side.

Element Reactant side Product side
$\mathrm{Zn}$ $1$ $1$
$\mathrm{C}$ $1$ $1$
$\mathrm{O}$ $3$ $3$

All the elements are already balanced

Balanced equation is:
$\mathrm{ZnCO}{}_3(\mathrm{s})\to \mathrm{ZnO}(\mathrm{s})+\mathrm{CO}{}_2(\mathrm{g})$
(Zinc carbonate) (Zinc oxide) (Carbon dioxide)
2. Type of reaction

Combination reaction: Reaction in which two or more reactants combine to form a single product. $\mathrm{A}+\mathrm{B}\to \mathrm{C}$

Decomposition reaction: Reaction in which reactant is broken down into two or more products in the presence of heat, light or electricity. $\mathrm{A}\to \mathrm{B}+\mathrm{C}$

Displacement reaction: Reaction in which one of the higher reactive element displaces less reactive element from its solution. $\mathrm{A}+\mathrm{BC}\to \mathrm{AC}+\mathrm{B}$ ( Here A is more reactive than B)

Double displacement reaction: Reaction in which ions of both the reactants interchange their place and form new compounds. $\mathrm{AB}+\mathrm{CD}\to \mathrm{AD}+\mathrm{CB}$

$\mathrm{ZnCO}{}_3(\mathrm{s})\to \mathrm{ZnO}(\mathrm{s})+\mathrm{CO}{}_2(\mathrm{g})$

Here $\mathrm{ZnCO}{}_3$ is getting decomposed into $\mathrm{ZnO}$ and $\mathrm{CO}{}_2$.
This is a decomposition reaction .