![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
已知: (1)NH 3 (g)+HCl(g)=NH 4 Cl(s); △H 1 =-76kJ·mol -1 (2)NH 3 (g)+H 2 O(l)=NH 3 ·H 2 O(aq); △H 2 =-35.1kJ·mol -1 (3)HCl(g)+HCl (aq); △H 3 =-72.3kJ·mol -1 (4)HCl (aq) NH 3 ·H 2 O(aq) =NH 4 Cl(aq)+H 2 O(l); △H 4 =-52.3kJ·mol -1 (5)NH 4 Cl(s)=NH 2 Cl(aq); △H 5 =? 根据盖斯定律,则(5)方程式中的反应热△H 5 为