Question

Calculate the percentage of water of crystallization in CuSO₄.5H₂O

(H = 1, O = 16, S = 32, Cu = 64)

Answer 1

Given :
Atomic mass of H 1
Atomic mass of O 16
Atomic mass of S 32
Atomic mass of Cu 64

Molar mass of CuSO4.5H₂O (64) + (32) + (9 x 16) + (10 x 1)

= 250

Molar mass of five water molecules (10 x 1) + (5 x 16)

= 90

Percentage of water of crystallization  = `(90 xx 100)/250`  = 36% water of crystallization.