Correct answer: Option C: 226.73 kJ
Reason:
Enthalpy of reaction is mathematically expressed as,
∑ΔHf products - ∑ΔHf reactants
In present case, ΔHf of C2H2(g) = 266.73 kJ,
ΔHf of H2(g) = ΔHf of C(s,graphite) = 0
Therefore, Enthalpy of reaction = 266.73 - 0
= 266.73 kJ
