Question

Give the balanced equation for the reaction with two different amphoteric oxides with caustic soda.

Answer 1

Part 1:- Reaction of Aluminium oxide with Sodium hydroxide (caustic soda):-

When Aluminium oxide reacts with Sodium hydroxide, Sodium aluminate and water is formed as the product.

$\underset{\mathrm{Aluminium}\mathrm{oxide}}{{\mathrm{Al}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}\left(\mathrm{aq}\right)}\stackrel{∆}{\to }\underset{\mathrm{Sodium}\mathrm{Aluminate}}{2{\mathrm{Na}}_2{\mathrm{AlO}}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

Part 2:- Reaction of Zinc oxide with Sodium hydroxide (caustic soda):-

When Zinc oxide reacts with Sodium hydroxide, Sodium zincate and water is formed as the product.

$\underset{\mathrm{Zinc}\mathrm{oxide}}{\mathrm{ZnO}\left(\mathrm{s}\right)\left(\mathrm{white}\right)}+\underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}\left(\mathrm{aq}\right)}\stackrel{∆}{\to }\underset{\mathrm{Sodium}\mathrm{zincate}}{2{\mathrm{Na}}_2{\mathrm{ZnO}}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

Therefore, the balanced chemical equation for two different amphoteric oxides with caustic soda are $\underset{\mathrm{Aluminium}\mathrm{oxide}}{{\mathrm{Al}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}+\underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}\left(\mathrm{aq}\right)}\stackrel{∆}{\to }\underset{\mathrm{Sodium}\mathrm{Aluminate}}{2{\mathrm{Na}}_2{\mathrm{AlO}}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$ and $\underset{\mathrm{Zinc}\mathrm{oxide}}{\mathrm{ZnO}\left(\mathrm{s}\right)\left(\mathrm{white}\right)}+\underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}\left(\mathrm{aq}\right)}\stackrel{∆}{\to }\underset{\mathrm{Sodium}\mathrm{zincate}}{2{\mathrm{Na}}_2{\mathrm{ZnO}}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$