Question

Explain the following: a) Plaster of Paris is stored in moisture proof container b)Milkman add baking soda in milk c)Bleaching powder is mixed in drinking water​

Answer 1

1. Plaster of Paris (POP) should be stored in a moisture-proof container because Plaster of Paris, a powdery mass, absorbs water (moisture) to form a hard solid known as gypsum.
2. As this milk is slightly more alkaline than other, therefore, acid produced to set into curd will be neutralized by baking soda added by milkman. Hence, this milk takes a longer time to set as curd
3. To make this, mix 15 gram bleaching powder with 100 ml (half glass) water and keep for 15-20 minutes. Clear water derived from this could be used as chlorine solution. To purify drinking water from bacteria, add 8 drops (0.5 ml) of chlorine solution in 1 litre of water to purify it.

Answer 2

Answer:

1) Plaster of Paris in contact with moisture ( water) changes to solid hard mass, gypsum. Therefore, it gets wasted. Hence it should be stored in moisture proof container.

2) By adding a very small amount of baking soda to fresh milk, the milkman keeps the milk unspoiled for little more time than usual time.

3) Bleaching powder, CaOCI2 or calciumoxychloride is used to kill germs and bacteria of water because it contains chlorine element, which is good disinfecting agent.

I hope this will help.