Hydroxide is a polyatomic ion consisting of oxygen and hydrogen:

⁻O−H

It has a charge of −1. Hydroxide is one of the simplest of the polyatomic ions.

The term hydroxyl group is used to describe the functional group -OH when it is a substituent in an organic compound. Organic molecules containing a hydroxyl group are known as alcohols (the simplest of which have the formula C_nH_2n+1-OH).

See also

• Hydronium
• Potassium hydroxide
• Sodium hydroxide
• Iron hydroxide
• Oxide