Ethyne, $\text{C}_2\text{H}_2$, undergoes complete combustion, as represented by the equation. $\text{H-C}\equiv\text{C-H} + 2\tfrac{1}{2}\,\text{O}=\text{O} \rightarrow \text{H}_2\text{O} + 2\text{CO}_2$ Using the average bond enthalpies in the table, calculate the enthalpy change of combustion of ethyne.
- A$-980\ \text{kJ mol}^{-1}$
- B$-540\ \text{kJ mol}^{-1}$
- C$+540\ \text{kJ mol}^{-1}$
- D$+980\ \text{kJ mol}^{-1}$