The general chemical equation for the reaction between metals and acids to produce hydrogen gas is:

Metal(s) + Acid(aq) ⟶ Metal Salt(aq) + Hydrogen Gas(g)

This reaction involves the metal reacting with an acid to form a metal salt and release hydrogen gas. The specific metal salt formed depends on the metal and acid involved in the reaction. For example, with hydrochloric acid, the metal chloride is formed, while sulfuric acid produces the corresponding metal sulfate. This type of reaction is a common way to generate hydrogen gas in the laboratory and is utilized in various chemical processes.