Question

Write a balanced chemical equation for the following.

Passing carbon dioxide through lime water.

Answer 1

• When carbon dioxide is passed through lime water, it forms a precipitate of calcium carbonate along with water. This is a precipitation reaction.

Chemical equation -

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

Reactant side	Product side
Calcium (Ca) = 1	Calcium (Ca)= 1
Oxygen ( O) = 4	Oxygen ( O) = 4
Hydrogen (H) = 2	Hydrogen (H) = 2
Carbon (C) = 1	Carbon (C) = 1

Balanced chemical equation - In this reaction both the reactant and the product side atoms are equal in number so no need to add any coefficient.

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