Give reasons for the following:(i) Only one half of water molecule is shown in the formula of Plaster of Paris.(ii) Sodium hydrogen carbonate is used as an antacid.(iii) On strong heating, blue coloured copper sulphate crystals turn white.

Give reasons for the following:(i) Only one half of water molecule is

1.	Give reasons for the following:(i) Only one half of water molecule is shown in the formula of Plaster of Paris.(ii) Sodium hydrogen carbonate is used as an antacid.(iii) On strong heating, blue coloured copper sulphate crystals turn white.
Answer» SOLUTION :(i) Actually two formula units of `CaSO_4` share one molecule of water. Hence one formula unit shares half molecule of water. (ii) Sodium hydrogen carbonate is an alkaline substance. It NEUTRALISES excess acidity in the stomach. Therefore, it is used as an ANTACID. (iii) On heating, blue copper SULPHATE crystals lose water of crystallisation. Anhydrous copper sulphate is white. `underset(Blue)(CuSO_4"."5H_2O)overset(HEAT)rarrunderset(White)(CuSO_4"."5H_2O)`