Question

1. The chemical formula of gypsum is :
(A) CaSO4 2H,0
(B) CaSO4 1/2 H20
(C) CaSO4.3/2 H2O
(D) CaSO4
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Answer 1

Answer:

The bonding nature of water in gypsum, CaSO4·2H2O, and hemihydrate, CaSO4·1/2H2O, was suggested by characteristic absorption bands of water and sulphate ions. The infrared spectral data indicate the presence of anion water in gypsum and hemihydrate through hydrogen bonding. Negative shifting of bending vibration of SO4 ion and lowering and broadening of the O–H stretching vibration at around 3600 cm−1 indicate the presence of both anion water and hydrogen bonding in gypsum and hemihydrate

Answer 2

Answer:

D is correct answer.

Explanation:

CaSO4