NH4 + H2O = NH3*H2O + H+
Mg + 2H+ = Mg2+ + H2 (放热)
二者合并,氨水分解
2NH4 + 2H2O +Mg = Mg2+ + H2 + 2NH3 + 2H2O
前后相减,2NH4 + Mg = Mg2+ + H2 + 2NH3