Answer to Question #15735 in Chemistry for Porscha

Question

how many grams of epson salt, MgSo4*10H2O are needed in order to produce 1.25g of water?

Answer 1

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.