Difference between revisions of "Hydroxide Ion (Chemistry)"
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: MgO(s) + 2H<sub>2</sub>O → Mg<sup>+2</sup>(aq)+2OH<sup>-</sup>(aq) | : MgO(s) + 2H<sub>2</sub>O → Mg<sup>+2</sup>(aq)+2OH<sup>-</sup>(aq) | ||
: CaO(s) + 2H<sub>2</sub>O → Ca<sup>+2</sup>(aq)+2OH<sup>-</sup>(aq) | : CaO(s) + 2H<sub>2</sub>O → Ca<sup>+2</sup>(aq)+2OH<sup>-</sup>(aq) | ||
| − | : Al<sub>2<sub>O<sub>3</sub>(s) + 3H<sub>2</sub>O → 2Al<sup>+3</sup>(aq)+3OH<sup>-</sup>(aq) | + | : Al<sub>2</sub>O<sub>3</sub>(s) + 3H<sub>2</sub>O → 2Al<sup>+3</sup>(aq)+3OH<sup>-</sup>(aq) |
Revision as of 12:52, 6 January 2019
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.
- Na2O(s) + H2O → 2Na+(aq)+2OH-(aq)
- K2O(s) + H2O → 2K+(aq)+2OH-(aq)
- MgO(s) + 2H2O → Mg+2(aq)+2OH-(aq)
- CaO(s) + 2H2O → Ca+2(aq)+2OH-(aq)
- Al2O3(s) + 3H2O → 2Al+3(aq)+3OH-(aq)