Calculate the enthalpy for this reaction: 2C(s) + H2() → C2H2(g)
ΔH° = ??? kJ

Given the following thermochemical equations:
C2H2(g) + (5/2)O2(g) → 2CO2(g) + H2O(ℓ)
ΔH° = -1299.5 kJ

C(s) + O2(g) → CO2(g)
ΔH° = -393.5 kJ

H2(g) + (1/2)O2(g) → H2O(ℓ)
ΔH° = -285.8 kJ