13 г                                                Х г  Zn           +          2HCl      -gt;       ZnCl2      +      H2n = 1 моль                                  n = 1 мольMr = 65 г/моль                           Mr = 135 г/мольm = 65 г                                       m = 135 г13 г Zn    -    Х г ZnCl265 г Zn    -    135 г ZnCl2m(ZnCl2) = 13 * 135 / 65 = 27 г