Question

What is the action of water on magnesium? Write equations of the chemical reactions involved.

Answer 1

Magnesium metal does not react with cold water. Magnesium reacts with hot water to form magnesium hydroxide and hydrogen.

\[\ce{\underset{Magnesium}{Mg_{(s)}} + \underset{(Hot)}{\underset{Water}{2H2O_{(l)}}} -> \underset{Magnesium hydroxide}{Mg(OH)2_{(aq)}} + \underset{Hydrogen}{H2_{(g)}}}\]

Magnesium reacts very rapidly with steam to form magnesium oxide and hydrogen.

\[\ce{\underset{Magnesium}{Mg_{(s)}} + \underset{Steam}{H2O_{(g)}} -> \underset{Magnesium oxide}{MgO_{(s)}} + \underset{Hydrogen}{H2_{(g)}}}\]