化学反应N₂＋3H₂＝ 2NH₃的能量变化如下图所示，该反应的热化学方程式是

A．N2(g)＋3H2(g) ＝ 2NH3(l)；⊿H ＝ 2(a—b—c)kJ·mol^－^1

B．N2(g)＋3H2(g) ＝ 2NH3(g) ；⊿H ＝ 2(b—a)kJ·mol^－^1

C．N2(g)＋H2(g) ＝ NH3(l) ；⊿H ＝ (b＋c—a)kJ·mol^－^1[^来源^:Z&xx&k.Com]

D．N2(g)＋H2(g) ＝NH3(g) ；⊿H ＝ (a＋b)kJ·mol^－^1