Here's a breakdown:
* Metal oxide is a compound containing a metal cation and an oxide anion (O²⁻).
* Water is a polar molecule with a slightly positive hydrogen side and a slightly negative oxygen side.
* Hydroxide is a compound containing a metal cation and a hydroxide anion (OH⁻).
The reaction:
The positive hydrogen side of water attracts the negative oxide ion in the metal oxide, while the negative oxygen side of water attracts the positive metal ion. This results in a double displacement, where the oxide ion from the metal oxide combines with a hydrogen ion from water to form a hydroxide ion (OH⁻), and the metal ion from the metal oxide combines with the hydroxide ion to form the metal hydroxide.
General equation:
Metal oxide + Water → Metal hydroxide
Example:
Sodium oxide (Na₂O) reacts with water to form sodium hydroxide (NaOH):
Na₂O + H₂O → 2NaOH
This reaction is also classified as an exothermic reaction, as it releases heat.
Note: Not all metal oxides react with water to form hydroxides. The reactivity depends on the metal's position in the reactivity series. For example, oxides of alkali metals and alkaline earth metals are generally reactive with water, while transition metal oxides are generally less reactive.
