Question: 49: \mathrm{CaCl}_{2} and \mathrm{Ca}(\mathrm{OCl})_{2} are components of :
(1) gypsum
(2) Portland cement
(3) bleaching powder
(4) lime water
Answer: Option (3)
Explanation:
Bleaching powder is prepared by passing chlorine gas over dry slaked lime.
\mathrm{Ca(OH)}_{2}+\mathrm{Cl}_{2} \rightarrow \mathrm{Ca(OCl)Cl}+\mathrm{H}_{2}\mathrm{O}The chemical composition of bleaching powder is represented as a mixture containing calcium hypochlorite and calcium chloride.
\mathrm{Ca(OCl)}_{2} provides bleaching and disinfecting properties.
\mathrm{CaCl}_{2} is also present as a component in bleaching powder.
Gypsum is \mathrm{CaSO}_{4}\cdot 2\mathrm{H}_{2}\mathrm{O}
and does not contain these compounds.
Portland cement consists mainly of calcium silicates and aluminates.
Lime water is an aqueous solution of \mathrm{Ca(OH)}_{2}.
Therefore, \mathrm{CaCl}_{2} and \mathrm{Ca(OCl)}_{2} are components of bleaching powder.