Verified answer

      96 г                                      Х г

     2Mg       +         O2      =       2MgO

n = 2 моль                                 n = 2 моль

Mr = 24 г/моль                          Mr = 40 г/моль

m = 48 г                                     m = 80 г

96 г Mg    -    Х г MgO

48 г Mg    -    80 г MgO

m(MgO) = 96 * 80 / 48 = 160 г