Step-by-step explanation:
When zinc chemically reacts with hydrochloric acid in chemical reaction then it leads to the formation of zinc chloride along with evolution of hydrogen gas.
Chemical equation which represents this chemical reaction is as follows.

Number of atoms on reactant side are as follows.
Zn = 1
H = 1
Cl = 1
Number of atoms on product side are as follows.
Zn = 1
H = 2
Cl = 2
Hence, to balance this equation we will multiply HCl by 2 on reactant side. Therefore, the balanced chemical equation is as follows.
