Please help! Using table of average bond energies below the (trianglesymbol)H for the reaction is ___kJ

815kJ

Explanation:

ΔH = product energy - reactant energy

ΔH = [(I-C) × 2 + (C-H) × 4 + (C-C)] - [(C-H) × 2 + (C≡C)]

ΔH = [(240 × 2) + (413 × 4) + 348] - [ (413 × 2 ) + 839]

ΔH = [ 480 +1652 + 348] - [826 +839]

∴ ΔH = 815kJ

it is stable as it is in group 0 which have full outer shells of electrons