Question

Bleaching powder contains which of the following anions?
(A) $C{l^ - },\,OC{l^ - }$
(B) $Cl{O_3}^ -,\,C{l^ - }$
(C) $Cl{O_3}^ -,\,OC{l^ - }$
(D) $OCl_2^{2 - }$

Answer 1

Hint: When this Slaked lime is treated with chloride it gets converted into an inorganic compound that works as a bleaching agent in the swimming pools. Slaked lime is formed when \[CaO\] reacts with water and forms calcium hydroxide.

Complete step by step answer:
- Bleaching powder is pale yellowish in color with a pungent smell of chlorine. It gets dissolved in water but due to the impurities that are present, we are not able to observe a clear solution. The chemical formula of bleaching powder is $CaOC{l_2}$ and its chemical name is Calcium hypochlorite.
- When this Slaked lime is treated with chloride it gets converted to calcium hypochlorite also known as bleaching agent. It is an exothermic process. Calcium hypochlorite is used in the cleaning of swimming pools.
- Calcium hypochlorite can also be used as an oxidising agent in organic chemistry. It is used in the haloform reaction to manufacture chloroform. Calcium hypochlorite is also used for oxidation of thiol and sulphide by-products.
- When you dissociate $CaOC{l_2}$ into ions, it dissociates into one cation and two anions. The ions that formed upon dissociation are calcium ion, chloride ion, and hypochlorite ion.
\[CaOC{l_2}\, \to Ca_2^ + + \,\,OC{l^ - } + \,\,C{l^ - }\]
Hence, anions in bleaching powder are chloride ion and hypochlorite ion \[OC{l^ - },\,\,C{l^ - }\].

Therefore, option (A) is correct.

Additional Information: In endothermic reactions, the heat absorbs and cools the temperature of the surroundings while in an exothermic reaction heat is released into the surroundings leading to the rise in temperature.

Note:
Bleaching powder is formed when $Ca{(OH)_2}$ is treated with chlorine gas. Bleaching powder is commonly used to sanitize drinking water and swimming pools. It is also used to bleach clothes in the laundry.