Hydrogen cyanide is a highly poisonous, volatile liquid. It can be prepared by the reaction CH4(g) +

Question:

Hydrogen cyanide is a highly poisonous, volatile liquid. It can be prepared by the reaction
CH4(g) + NH3(g) → HCN(g) + 3H2(g)
What is the heat of reaction at constant pressure? Use the following thermochemical equations:
N2(g) + 3H2(g) → 2NH3(g); ∆H = –91.8 kJ
C(graphite) + 2H2(g) → CH4(g); ∆H = –74.9 kJ
H2(g) + 2C(graphite) + N2(g) → 2HCN(g);
∆H = 270.3 kJ