11,2 л                                                                    Х г

     C5H12        +       8 O2       =       5CO2       +        6H2O

n = 1 моль                                                              n = 6 моль

Vm = 22,4 л/моль                                                 Mr = 18 г/моль

V = 22,4 л                                                             m = 108 г

11,2 л С5Н12     -    Х г н2О

22,4 л С5Н12      -    108 г Н2О

m(H2O) = 11,2 * 108 / 22,4 = 54 г