Question

(iv) Select the incorrect statement with respect to gypsum.
a. it is slightly soluble in water
b. it is also known as alabaster
c. on heating gypsum at 373 Kelvin it loses water molecules and becomes calcium sulphate hemihydrate
d. chemical formula of gypsum is CaSO4.12 H2O​

Answer 1

The correct option is d.

• Gypsum is moderately soluble in water.
• Alabaster is a soft mineral used for craving. It is a type of gypsum so, gypsum is also known as alabaster.
• On heating gypsum at 373 Kelvin, it loses water molecules and becomes calcium sulphate hemihydrate. The reaction is-

$CaSO_4.2H_2O\rightarrow CaSO_4.1/2H_2O+3/2H_2O$

• The chemical formula of gypsum is$CaSO_4.2H_2O$.
• Thus the wrong statement about gypsum is d.

Answer 2

Answer:

Option D is right

Explanation:

• Gypsum is CaSO4.2H2O