Explain the reactions of different metals with hot water, cold water and steam. Give one example with a proper balanced chemical equation. Name two metals which do not react with any form of water.
i. Cold water:
Sodium metal reacts violently with water. The reaction is so violent and exothermic that the evolved hydrogen immediately catches fire. The reaction is:
2Na + H2O → 2NaOH + H2 + heat energy
ii. Hot water:
Magnesium reacts with hot water to form magnesium hydroxide and hydrogen. The reaction is:
Mg + 2H2O → Mg(OH)2 + H2
iii. Steam:
Aluminium does not react either with cold or hot water. It reacts with steam to form the aluminium oxide (Al2O3) and hydrogen. The reaction is:
2Al + 3H2O → Al2O3 + 3H2
Metals such as lead, copper, silver, and gold do not react with water at all.