Question

Calculate the percent composition of water in zinc sulfate heptahydrate (ZnSO4* 7H2O)

Answer 1

Given :

ZnSO₄.7H₂O

To find :

Percentage Composition of water in ZnSO₄.7H₂O.

Solution :

Zn = 65

S = 32

O = 16

H = 1

ZnSO₄ = 65 + 32 + 4×16

           = 65 + 32 + 64

           = 161

H₂O = 2×1 + 16

       = 2 + 16

       = 18

Formula Mass of ZnSO₄.7H₂O = 161 + (7×18)

                                                  = 161 + 126

                                                  = 287

Percentage of water = (126 / 287)×100

                                  = 43.9%

Percentage composition of water in ZnSO₄.7H₂O = 43.9%