a) M CuSO4*5H2O=64 g/mol+32 g/mol+4*16 g/mol+5*18 g/mol=250 g/mol
b) M FeSO4*7H2O=56 g/mol+32 g/mol+4*16 g/mol+7*18 g/mol=278 g/mol
c) M CaCl2*6H2O=40 g/mol+2*35,5 g/mol+6*18 g/mol=219 g/mol
d) M Na2SO4*10H2O=2*23 g/mol+32 g/mol+4*16 g/mol+10*18 g/mol=322 g/mol
