Core Quantitative Chemistry: Formula
Slide
25
of 37
Water of Crystallization: Solution
Mass of water in 1 mole of NiSO
4
·
x
H
2
O = molar mass of NiSO
4
·
x
H
2
O
-
molar
mass of NiSO
4
(since molar ratio of NiSO4
·
x
H2O: NiSO4= 1:1)
= 263
-
154.77 = 108 g
Number of moles of water
Therefore,
x
= 6.
That is, in every mole of NiSO
4
·
x
H
2
O, there are 6 moles of water molecules.
Or, in every formula unit of NiSO
4
·
x
H
2
O, there are 6 molecules of water.