The formula of the hydrate is MnCl2.4H2O
calculation
find the moles of MnCl2 and H2O
moles= % composition/ molar mass
% composition of MnCl2 = 100- 36.41=63.59 %
moles of MnCl2 = 63.59/ 125.84= 0.505 moles
moles of H2O= 36.41/18 = 2.022 moles
find the mole ratio by dividing each moles with smallest moles (0.505)
that is MnCl2 = 0.505/0.505=1
H2O = 2.022/0505 = 4
therefore the formula = MnCl2.4H2O
