Answer:

3 How caustic soda obtained ? Mention its uses Equipon?

Ans: Caustic Soda Lye is one of the most widely used chemicals in the industry. ... The main applications are water treatment and water purification, as cleaning agent, or a wide range of usesin chemical industry like starch production or for the desulphurization in the petrochemical industry.

4 HOW es plaster of Paris prepared2 write the reaction ?

Ans: Plaster of Paris is prepared by heating gypsum at 373 K. On heating, it loses water molecules and becomes calcium sulphate hemihydrate (CaSO4. 1/2 H2O) which is called Plaster of Paris.