Metal oxides are basic

Metal oxides are basic; they react with water to form bases such as hydroxides.

METAL + OX HIDE (OXIDE) = BASE DRUM (BASE)

E.g. sodium oxide + water → sodium hydroxide

Na₂O + H₂O → 2NaOH

Other examples of metal oxides include potassium oxide K₂O and calcium oxide CaO.

Non-metal oxides are acidic

Because metal oxides are basic, non-metal oxides are acidic. They react with water to form acids.

E.g. carbon dioxide + water → carbonic acid

CO₂ + H₂O → H₂CO₃