Acids react with some metals to produce a salt and hydrogen gas. The metal seems to disappear as it dissolves in the acid, and bubbles of hydrogen are given off. The general word equation is: acid + metal → salt + hydrogen.
The salt formed depends on the acid. Hydrochloric acid makes chlorides and sulfuric acid makes sulfates. The first part of the salt's name comes from the metal. You need to know the reactions of magnesium, zinc and iron with hydrochloric acid and sulfuric acid.
For example, magnesium reacts with hydrochloric acid to make magnesium chloride and hydrogen: Mg + 2HCl → MgCl2 + H2. Zinc reacts with sulfuric acid to make zinc sulfate and hydrogen: Zn + H2SO4 → ZnSO4 + H2. Iron reacts with hydrochloric acid to make iron(II) chloride and hydrogen. Magnesium fizzes fastest of the three.
Hydrogen can be identified by holding a lit splint at the mouth of the test tube. The gas burns with a squeaky pop.
