2 моль                                                   Х л

   Zn         +      H2SO4   =  ZnSO4    +    H2

n = 1 моль                                             n = 1 моль

                                                              Vm= 22,4 л/моль

                                                              V = 22,4 л

2 моль Zn  -   X л Н2

1 моль Zn   -  22,4 л Н2

V(H2) = 2 * 22,4 = 44,8 л