md=ms*c/100=300*5/100=15 (g)
M CuSO4*5H2O=160+90=250
250gcristalohidrat.........160gCuSO4
x g `` ..........15 g CuSO4
x=23,43 (g) CuSO4*5H2O
deci 300 g solutie= 23,43g cristalohidrat+ y g H2O ==>
y (masa apei adaugate)= 300-23,43= 276,57 (g) H2O
VH2O= 276,57g*1g/cm3=.....