Question

Balance each one of the following chemical equations:

${\mathrm{BaCl}}_2+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{BaSO}}_4+\mathrm{HCl}$

Answer 1

Step 1: Balanced chemical equations

Chemical equations that obey the law of conservation of mass are called balanced chemical equations. The count of atoms of each element in the reactant side will be equal to that on the product side in a balanced chemical equation. The trial and error method is used to balance chemical equations by adding coefficients to each species.

Step 2: Reaction between barium chloride and sulphuric acid

Aqueous solutions of barium chloride $\left({\mathrm{BaCl}}_2\right)$ and sulphuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ react to form a solid precipitate of barium sulphate $\left({\mathrm{BaSO}}_4\right)$ and hydrochloric acid solution $\left(\mathrm{HCl}\right)$. It is an example of a precipitation reaction because a white precipitate of barium sulphate is formed.

The equation for the reaction is:

${\mathrm{BaCl}}_2+{\mathrm{H}}_2{\mathrm{SO}}_4\to {\mathrm{BaSO}}_4+\mathrm{HCl}$

The number of atoms of each element in the reaction is:

Element	Reactant side	Product side
Ba	1	1
Cl	2	1
H	2	1
S	1	1
O	4	4

Step 3: Balancing atoms on both sides

To balance hydrogen and chlorine atoms, add a coefficient of 2 to hydrochloric acid. Then the equation becomes balanced.

Therefore, the balanced equation for the reaction is:

${\mathrm{BaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)$