IIT-JEE 2012 · Paper 2, Chemistry question 27

Using the data provided, calculate the multiple bond energy (kJ mol⁻¹) of a C≡C bond in $\ce{C2H2}$. That energy is (take the bond energy of a C-H bond as 350 kJ mol⁻¹.)

$\ce{2C(s) + H2(g) -> C2H2(g)}$, $\Delta H=225$ kJ mol⁻¹

$\ce{2C(s) -> 2C(g)}$, $\Delta H=1410$ kJ mol⁻¹

$\ce{H2(g) -> 2H(g)}$, $\Delta H=330$ kJ mol⁻¹