What mass of water is in 150 g of mgso4*7h2o

The mass of water that is in 150 g of Mgso4.7H20 is calculated as follows

mass of water = molar mass of H20 in MgSO4.7H20 / total molar mass of MgSO4.7H20 x mass (150g)

molar mass of h20 = 18 x 7 = 126 g/mol since there is 7 water molecules

molar mass of MgSO4.7H20 = 24 + 32 + (16x4) + (18x7) = 246g/mol

Mass of water is therefore = 126 g/mol/246g/mol x150g = 76.8 g