how many grams of epson salt, MgSo4*10H2O are needed in order to produce 1.25g of water?
The Epsom salt is MgSO4*7H2O. The molecular mass of MgSO4*7H2O is 246 g/mol. The water can be produced y the follow equation: MgSO4*7H2O -- temperature ---> MgSO4 + 7H2O The one mole of MgSO4*10H2O can produce 7 moles of water. We need (1.25 g / 18 g/mol)=0.0694 moles of water. Thus, the amount of epsom salt is 0.0694/7=0.01 moles. The mass of MgSO4*7H2O is m(MgSO4*7H2O)=0.01 mol * 246 g/mol = 2.46 g.