![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-53/ti_inject-812ce.png)
反应N 2 +3H 2 ≒ 2NH 3 的能量变化如图所示,其热化学方程式正确的是( )
A.
N 2 (g)+3H 2 (g) ≒ 2NH 3 (l) Δ H =+2( b + c - a )kJ·mol -1
B.
N 2 (g)+3H 2 (g) ≒ 2NH 3 (g) Δ H =+2( b - a )kJ·mol -1
C.
N 2 (g)+3H 2 (g) ≒ 2NH 3 (l) Δ H =-2( b + c - a )kJ·mol -1
D.
N 2 (g)+3H 2 (g) ≒ 2NH 3 (g) Δ H =-( a + b )kJ·mol -1