Question

What do you understand by the term "equation is balanced'?

Answer 1

Balanced equation:

• When the numbers of atoms of each type involved in a chemical reaction are the same on the reactant and product sides of the equation is known as a balanced equation.
• Example: Consider a reaction between zinc and hydrochloric acid:

Word equation:

$\mathrm{Zinc}+\mathrm{Hydrochloric}\mathrm{acid}\to \mathrm{Zinc}\mathrm{chloride}+\mathrm{Hydrogen}$

Skeletal reaction:

$\mathrm{Zn}\left(\mathrm{s}\right)+\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{ZnCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$

Balanced chemical reaction:

• In order to balance this reaction, a stoichiometric coefficient $2$ is added in front of $\mathrm{HCl}$, which balances all the other atoms too.
• The balanced chemical equation can be depicted as:

$\mathrm{Zn}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{ZnCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$