Question

Give reason for the following-

The reaction of aluminium with steam stops after some time.

Answer 1

The reaction of metal with water-

• When a metal reacts with water to form their hydroxides and realise hydrogen gas.
• Metal + water $\to$Metal hydroxide + Hydrogen gas
• The metal reacts on the basis of the reactivity series of metal.
• The different metal reacts with a different phase of water.
• For example-
• Highly reactive metal can even react with cold water.
• Less reactive metals reacts with warm/hot water.
• Least reactive metal react only with steam.

The reaction of aluminium with steam stops after some time because-

• Aluminium reacts with steam to form aluminium oxide.
• $2\mathrm{Al}\left(\mathrm{s}\right)+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\to {\mathrm{Al}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)$
• The layer of aluminium oxides prevents aluminium to get a further reaction.
• The reaction stopped after some time.