Question

A solution of a substance 'X' is used for White washing
(a) name the substance 'X' and write it's formula
(b) write the reaction of a substance 'X' named in (a) with water ​

Answer 1

The substance 'X' is calcium oxide or quick lime.

• Quicklime is used for whitewashing as it produces calcium hydroxide when it reacts with water.
• It absorbs carbon dioxide from the environment, as a result, it produces calcium carbonate which creates a hard coating on the walls.
• The equation for the reaction of quick lime with water is:

$CaO+H_{2}O$ → $Ca(OH)_{2}$