Question

Write the balanced chemical equations for the following reactions.

(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water

Answer 1

Balanced chemical equation: A balanced chemical equation is the representation of a chemical reaction in which the number of atoms of each element is the same on both the reactant and product sides.

Word equation to symbolic equation:

• In the given reaction, Calcium hydroxide reacts with Carbon dioxide to form Calcium carbonate and Water.
• The chemical reaction can be represented as:

$\underset{\mathrm{Calcium}\mathrm{hydroxide}}{\mathrm{Ca}(\mathrm{OH}{)}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

Balancing the Chemical Equation:

Step 1: Write the number of atoms of each element

$\underset{\mathrm{Calcium}\mathrm{hydroxide}}{\mathrm{Ca}(\mathrm{OH}{)}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

Element	Reactant side	Product Side
$\mathrm{Ca}$	$1$	$1$
$\mathrm{O}$	$4$	$4$
$\mathrm{C}$	$1$	$1$
$\mathrm{H}$	$2$	$2$

From the table, it is clear that the atoms of all the elements are balanced.

Hence, the balanced chemical equation is as follows: $\underset{\mathrm{Calcium}\mathrm{hydroxide}}{\mathrm{Ca}(\mathrm{OH}{)}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$