APPENDIX
Bond Enthalpies

AVERAGE SINGLE BOND ENTHALPIES (kJ/mol) AT 25o C

H
C
N
O
F
Si
P
S
Cl
Br
I
H
436
413
391
463
565
 318
322
347
432
366
299
C
413
346
305
358
485
---
---
272
339
285
 213
N
391
305
163
201
283
---
---
---
192
 243
---
O
463
358
201
146
184
452
335
---
218
201
201
F
565
485
283
184
155
565
490
284
253
249
278
Si
318
---
---
452
565
222
---
293
381
310
234
P
322
---
---
335
490
---
201
---
326
---
184
S
347
272
---
---
284
293
---
226
255
213
---
Cl
432
339
192
218
253
381
326
255
242
216
208
Br
366
285
243
201
249
310
---
213
216
193
175
I
299
213
---
201
278
234
184
---
208
175
151
 
Double Bonds 
(kJ/mol)
Triple Bonds 
(kJ/mol)
 
C=C
602
 C*C
835
O=O
498
C=O
732
 C*O
1072
N=O
607
N=N
418
 N*N
945
C=N
615
 C*N
887