Question

5. (15 points) Estimate the C-C bond energy from the provided information below: CH.(g) + H2(g) → CH.(g) AH®rxn-- 137 kJ Bond Bond Energy (kJ/mol) C-C611 C-H 414 C=C 837 H-H 436

Answer 1

Ang. Bond Energy or Bond enthalpy: Bond energy is defined as the amount of energy Released for the formation of I mole of bonds from isolated gaseous atoms Sgaseous state). OR amount of energy which is required for the dissociation of one mole of bonds present between atoms C goseous molecules). Guven Heachion - Cg Hq (g) + Hygg) - Shag Atiwn = -134 KJ I (= gt H-1HG H -C- C-H g) SH I 11 H Arxntº = E Bond enougy Creactants ) – E Bond energy Product) H = BEL (=CH + H-H - BEH-C-(-H - 1 H (BE = Bond energy) -137K5 = [BŁ(C=C) + 4 BE (C-1) + BE (1-4) ] - [8:8:(-6) + 6 BE(C-H)] - 137 = [(611 KI mol) +(4 x 419 KI molº) + (136 xsmort)] - - [ BE (C-4)] + 6 x 41 4k 5 mai

-134 = (611 + 1656 + 436) - [ BE (C-C) +2484) - 137 = 2703 - BE (GC) - 2484 -137 = 219 - BE ((-) -137 = 219- BE CC-C) BE CC-c) = 219 +137 BE(C-c) = 356 ks mo!! The c-c bond energy is 356 kJ molt