57,1 г                                                         Х г   FeSO4     +      BaCl2    -gt;    FeCl2     +    BaSO4n = 1 моль                                                    n = 1 мольMr = 152 г/моль                                           Mr = 233 г/мольm = 152 г                                                     m = 233 г57,1 г FeSO4    -    Х г BaSO4152 г FeSO4    -    233 г BaSO4m(BaSO4) = 57,1 * 233 / 152 = 87,5 г