Question

Name the substance which on treatment with chlorine yields bleaching powder.

Answer 1

Hint : The substances which are used to lighten the color of reaction mixture are said to have bleaching properties. Chlorine has bleaching properties and is toxic in nature. Slaked lime on treatment with chlorine yields bleaching powder which is less hazardous than chlorine.

Complete Step By Step Answer:
The substances which are used to lighten the color of reaction mixture are said to have bleaching properties. Chlorine has bleaching properties and is toxic in nature. Calcium hydroxide i.e. $ Ca{{(OH)}_{2}} $ also called Slaked lime on treatment with chlorine yields bleaching powder i.e. $ CaOC{{l}_{2}} $ which is less hazardous than chlorine. This is illustrated in the following diagram.
 $ Ca{{(OH)}_{2}}+C{{l}_{2}}\to CaOC{{l}_{2}}+H_{2}^{{}}O $
From the above diagram, we conclude that calcium hypochlorite i.e. $ CaOC{{l}_{2}} $ is formed by the reaction of slaked lime with chlorine. Bleaching powder has several day-today applications. For instance, calcium hypochlorite solution is used as disinfectant in the treatment of drinking water to make potable. Apart from that, it is also used as bleach to lighten the skin complexion and also in deodorants. However, it has several side effects including skin irritation and is hazardous to lungs when inhaled.
Therefore, slaked lime is the substance which on treatment with chlorine yields bleaching powder.

Note :
It is important to note that calcium hydroxide on treatment with chlorine yields bleaching powder. Chemically, bleaching powder is a calcium hypochlorite solution which is used as disinfectant in the treatment of drinking water to make it potable. Besides, it is also used as bleach to lighten the skin complexion.