Question

Bleaching powder is prepared from:
A. Caustic potash
B. Caustic soda
C. Slaked lime
D. Magnesium chloride

Answer 1

Hint- In this question first we will understand what is bleaching powder, then we will proceed further by finding how to obtain it. We will see the chemical process and chemical reaction involved in the preparation of bleaching powder.

Complete answer:
Bleaching powder- Bleaching powder is a pale yellowish powder existing with a strong smell of chlorine. It is soluble in water but due to the presence of impurities, we never observe a clear solution. Its chemical formula is $CaOC{l_2}$ with its chemical name as Calcium hypochlorite.
Bleaching powder is synthesized by the action of chlorine gas (produced from the chlor-alkali process) on dry slaked lime $Ca{\left( {OH} \right)_2}$ .
$Ca{\left( {OH} \right)_2} + C{l_2} \to CaOC{l_2} + {H_2}O$

Hence, bleaching powder is prepared from slaked lime.

So, the correct answer is option C.

Note- Bleaching Powder is used for bleaching dirty clothes in the laundry, as a bleaching agent for cotton and linen in the textile industry. It is a strong oxidizing agent hence used as an oxidizer in many industries. It is used as a disinfectant which is used for disinfecting water to make potable water.