Question

Write the reaction when zinc carbonate is heated.

Answer 1

Zinc carbonate (${\mathrm{ZnCO}}_3$):

• Zinc carbonate is an odorless, white sand-like solid.
• It is insoluble in water.
• It is used in cosmetics, ointments, porcelain, pottery and rubber.

Reaction:

• When Zinc carbonate is heated it gives Zinc oxide and Carbon dioxide.
• The white powdery solid Zinc carbonate when heated turns yellow.
• The carbon dioxide gas evolving is confirmed by passing this gas over lime water, it turns the lime water milky.
• The reaction involved is: $\underset{\mathrm{Zinc}\mathrm{carbonate}}{{\mathrm{ZnCO}}_3\left(\mathrm{s}\right)}\stackrel{\mathrm{Heat}}{\to }\underset{\mathrm{ZInc}\mathrm{oxide}}{\mathrm{ZnO}\left(\mathrm{s}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}$
• The above reaction is an example of a decomposition reaction in which Zinc Carbonate is decomposed into two new products i.e. Zinc oxide and Carbon dioxide.