Write a balanced chemical equation describing the reaction of zinc and hydrochloric acid.

The chemical formula for zinc is Zn, and HCl for hydrogen chloride. The complete balanced equation for these reactants would be:

Zn + 2 HCl → ZnCl₂ + H₂

The stoichiometric coefficient 2 for HCl is essential to obey the Law of Conservation of Mass. The elements before and after the reaction must be equal in amounts.