Question

We know that bleeching powder is a basic substance.We also know that if we rub a turmeric stain with base,it becomes dark red.I heard that bleeching powder can vanish any stain from white cloth.How that become possible?

Answer 1

Bleaching powder is a mixture of calcium hydroxide and chlorine gas
Calcium hydroxide (Ca(OH)2) is base. So we are called bleaching powder as base.
But he chlorine gas present in the bleaching powder will release oxygen in water. This oxygen will remove the stains of turmeric powder.
Cl2+H2O --> 2HCl + O
So bleaching powder is base due to presence of calcium hydroxide and bleaching powder will change colour due to present of chlorine gas.