Question

Available chlorine can be liberated from bleaching powder by the reaction with:
This question has multiple correct options

A. conc.${{\rm{H}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}$

B. dil.${{\rm{H}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}$

C. ${\rm{C}}{{\rm{O}}_{\rm{2}}}$

D. dil.${\rm{HN}}{{\rm{O}}_{\rm{3}}}$

Answer 1

Bleaching powder is a yellow coloured powder of strong smell of chlorine. The formula of bleaching powder is ${\rm{CaOC}}{{\rm{l}}_{\rm{2}}}$. The chemical name of bleaching powder is calcium hypochlorite. Although it is soluble in water but clear solution is not observed.

Complete step by step answer:
Now, we understand when bleaching powder liberates chlorine gas. The liberation of chlorine gas from bleaching powder occurs when it reacts with any dilute acids. Here, two dilute acids are given in the options. So, reactions of bleaching powder with these two dilute acids lead to liberation of chlorine gas. The chemical reactions are,

${\rm{CaOC}}{{\rm{l}}_{\rm{2}}} + {{\rm{H}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}\left( {dil.} \right) \to {\rm{CaS}}{{\rm{O}}_{\rm{4}}} + {{\rm{H}}_{\rm{2}}}{\rm{O}} + {\rm{C}}{{\rm{l}}_2}$

${\rm{CaOC}}{{\rm{l}}_{\rm{2}}} + {\rm{CaC}}{{\rm{l}}_{\rm{2}}} + 4{\rm{HN}}{{\rm{O}}_{\rm{3}}} \to 2{\rm{Ca}}{\left( {{\rm{N}}{{\rm{O}}_{\rm{3}}}} \right)_2} + 2{{\rm{H}}_{\rm{2}}}{\rm{O}} + {\rm{2C}}{{\rm{l}}_2}$

Hence, we can say that when bleaching powder reacts with dilute sulphuric acid $\left( {{{\rm{H}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}} \right)$ and dilute nitric acid $\left( {{\rm{HN}}{{\rm{O}}_{\rm{3}}}} \right)$, liberation of chlorine gas takes place.

Hence, correct answers are option A and D.

Additional Information:

The chlor alkali process is the one which produces sodium hydroxide, chlorine and hydrogen gas by the reaction of sodium chloride and water.

${\rm{2NaCl}} + {{\rm{H}}_{\rm{2}}}{\rm{O}} \to {\rm{2NaOH}} + {\rm{C}}{{\rm{l}}_2} + {{\rm{H}}_{\rm{2}}}$

As chlorine and alkali are produced, the process is named as chlor alkali process.
The production of bleaching powder is done by the reaction of calcium hydroxide (slaked lime) with chlorine.

Now, reaction of formation of bleaching powder is,

${\rm{Ca}}{\left( {{\rm{OH}}} \right)_{\rm{2}}} + {\rm{C}}{{\rm{l}}_{\rm{2}}} \to {\rm{CaOC}}{{\rm{l}}_{\rm{2}}} + {{\rm{H}}_{\rm{2}}}{\rm{O}}$

Note:
Bleaching powder is used for various purposes. In laundry, it is used in bleaching cloth to remove stains. In the linen and cotton industry, it acts as a bleaching agent. In many industries, it is used in various chemical reactions as oxidizer as it is a strong oxidizing agent. It is also used in disinfecting water.