Balance the equation : Zn + HCl → ZnCl₂ + H₂

The mass is always conserved in a chemical equation. So, all chemical equations must be balanced.

To balance a chemical equation, we need to put the same number of atoms on each side of the arrow.

Coefficients are used to balance a chemical equation.

In the above question, we add 2 as a coefficient of HCl. Because, in right hand side of the equation there are two Hydrogen and two chlorine atoms are present.