32 г                                                            Х г

    CuSO4       +        Fe     =      FeSO4     +    Cu

n = 1 моль                                                    n = 1 моль

M=159,5 г/моль                                            M = 63,5 г/моль

m=159,5 г                                                     m = 63,5 г

32 г CuSO4    -    Х г Cu

159,5 г CuSO4  -  63,5 г Cu

m(Cu) = 32 * 63,5 / 159,5 = 13 г