miu CuSO4*5H2O = 160+90 = 250 g/mol
250 g cristaloh. .............. 160 g CUSO4 .... 90 g H2O
200 g ................................ md ........................... m.apa
= 128 g = 72 g
=> ms.final = 800+200 = 1000 g
md = 128 g
stim ca c% = mdx100/ms
=> c% = 128x100/1000 = 12,8%