8 г                                                                 Х л    Са       +        2Н2О      =     Са(ОН)2     +     Н2n = 1 моль                                                      n = 1 мольMr =40 г/моль                                                Vm=22,4 л/мольm = 40 г                                                          V = 22,4 л8 г Са   -    Х л Н240 г Са   -  22,4 л Н2V(H2) = 8 * 22,4 / 40 = 4,48 л