Hydroxide Ion (Chemistry)
Contents
Key Stage 4
Meaning
A Hydroxide ion (OH-), is a positive ion of Hydrogen found in acid solutions.
About Hydroxide Ions
- When a basic compound dissolves in water it forms Hydroxide ions.
- Hydroxide ions are responsible for the corrosive properties of alkalis.
Examples
Metal Hydroxides form Hydroxide ions in water.
- NaOH(aq) → Na+(aq)+OH-(aq)
- KOH(aq) → K+(aq)+OH-(aq)
- Mg(OH)2(aq) → Mg+2(aq)+2OH-(aq)
- Ca(OH)2(aq) → Ca+2(aq)+2OH-(aq)
- Al(OH)3(aq) → Al+3(aq)+3OH-(aq)
Metal Oxides react with water to form Metal Hydroxides.
- NaO(s) + H2O → Na+(aq)+OH-(aq)
- KOH(aq) + H2O → K+(aq)+OH-(aq)
- Mg(OH)2(aq) + 2H2O → Mg+2(aq)+2OH-(aq)
- Ca(OH)2(aq) + 2H2O → Ca+2(aq)+2OH-(aq)
- Al(OH)3(aq) + 3H2O → Al+3(aq)+3OH-(aq)