Average Bond Energies, E, in kJ/mol
(kcal/mol) at 25 oC

Single Bonds

H C N O F Si P S Cl Br I  
436
(104.2) 		413
(99) 		391
(93.5) 		463
(111) 		565
(135) 		318
(76)		 322
(77) 		347
(83) 		432
(103.2) 		366
(87.5) 		299
(71.5) 		H
  346
(83) 		305
(73) 		358
(86) 		485
(116) 		300
(72) 		--- 272
(65) 		339
(81) 		285
(68) 		213
(51)		 C
  163
(39) 		201
(48) 		283
(68) 		--- --- --- 192
(46) 		243
(58)		 --- N
  146
(35) 		184
(44) 		452
(108) 		335
(80) 		--- 218
(52) 		201
(48) 		201
(48) 		O
  155
(37) 		565
(135) 		490
(117) 		284
(68) 		253
(60) 		249
(59.5) 		278
(66) 		F
  222
(53) 		--- 293
(70) 		381
(91) 		310
(74) 		234
(56) 		Si
  201
(48) 		--- 326
(78) 		--- 184
(44) 		P
  226
(54) 		255
(61) 		213
(51) 		--- S
  242
(58) 		216
(52) 		208
(50) 		Cl
  193
(46) 		175
(42) 		Br
  151
(36) 		I

Multiple Bonds

Double Bonds
kJ/mol (kcal/mol)		 Triple Bonds
kJ/mol (kcal/mol)
C=C 602 (144) C≡C 835 (200)
O=O 498 (119)    
C=O Aldehydes 732 (175)
Ketones 749 (179)		 C≡O 1072 (256)
N=O 607 (145)    
N=N 418 (100) N≡N 945 (226)
C=N 615 (147) C≡N 887 (212)