The reaction between a metal oxide and an acid produces a salt and water. The resulting mixture is warm. The kind of salt produced is dependent on the specific acid used.
Some examples of reactions between acids and metal oxides are copper oxide with hydrochloric acid and the combination of copper oxide with nitric acid. In the first reaction, the copper oxide reacts with hydrochloric acid to produce copper chloride and water. The reaction between copper oxide and nitric acid forms copper nitrate and water.
There are various ways in which acids react with different metal compounds. For example, an acid reacts with a metal hydroxide to also form a salt and metal. Acids combined with metal carbonates produce a salt, water and carbon dioxide.