Question

Sanitary worker uses a white chemical having a strong smell of chlorine gas to disinfect the water tank.
(a) Identify the chemical compound, and write its chemical formula.
(b) Give chemical equations for its preparation.
(c) Write its two uses other than disinfection.

Answer 1

(a) The chemical compound is bleaching powder $CaOC{l}_2$.

Bleaching powder is a white powder existing with a strong smell of chlorine. It is soluble in water.
It is commonly known as bleaching powder but its main ingredient is calcium hypochlorite.


(b) Calcium hydroxide on treatment with chlorine yields bleaching powder which is represented as ${\text{CaOCl}}_2$. The reaction involved is:

${\text{Ca(OH)}}_2+{\text{Cl}}_2\to {\text{CaOCl}}_2+{\text{H}}_{2}O$.


(c) It is used as a bleaching agent and disinfectant. It undergoes decomposition in the presence of carbon dioxide gas to release chlorine along with calcium carbonate. The reaction involved is given below:

${\text{CaOCl}}_2\text{(s)}+{\text{CO}}_2\text{(g)}\to {\text{CaCO}}_3\text{(s)}+{\text{Cl}}_2\text{(g)}$

Apart from being used as disinfectant, it is also used to bleach washed clothes and wood pulp in paper industries.

It is also used as an oxidising agent in chemical industries.