Question

Preparation and uses of
Sodium Hydroxide, Bleaching powder , Baking soda
, washing soda and Plaster
of paris
​

Answer 1

Answer:

Plaster of Paris is synthesized from gypsum (CaSO4.2H2O). When gypsum is heated at 373 K, it loses its water molecules to become calcium sulphate (plaster of Paris).

CaSO4.2H2O → CaSO4.1/2H2O + 3/2H2O

Washing soda is a whitish, odourless powder. Its chemical formula is Na2CO3 and is better known as sodium carbonate. It is hygroscopic in nature that is, it absorbs moisture from the air. It is highly soluble in water and forms strongly alkaline water solution.

Washing soda is synthesized through Solvay’s process. Solvay’s process involves the reaction of sodium chloride, ammonia and carbon dioxide in water.NaCl + NH3 + CO2 + H2O → NaHCO3 + NH4Cl

2 NaHCO3 → Na2CO3 + H2O + CO2

Na2CO3 + 10H2O → Na2CO3.10H2O

Baking soda is a white crystalline compound with a slightly salty taste. Its chemical formula is NaHCO3 and is generally known as sodium bicarbonate