Hydrate of magnesium sulphate undergoes dehydration upon action of heat. This process can be chemically represent as follows:
MgSO4.XH2O → MgSO4 + XH20
(5.018 g) (2.449 g) (2.569 g)
Number of moles of H2O evolved = [tex] \frac{2.569}{Molecular.weight} [/tex]
= [tex] \frac{2.569}{18} [/tex]
= 0.1427
Number of moles of MgSO4 generated after decomposition,
= [tex] \frac{2.449}{Molecular.weight} [/tex]
=[tex] \frac{2.449}{120.37} [/tex]
=0.0203
Now dividing both these numbers by the smallest one to get the mole ratio that exists between MgSO4 and H20
For H2O, [tex] \frac{0.1427}{0.0203} [/tex] = 7.02 ~7
Thus, formula of hydrate is MgSO4.7H2O
