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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: fairweather on February 16, 2009, 01:20:13 AM

Title: bond energy vs bond dissociation energy
Post by: fairweather on February 16, 2009, 01:20:13 AM

There are considerable differences between values from several tables and values from Handbook of Chemistry and Physics, 88th

Definitions, Differences and which is the right one to express energy required to rupture the bonds shown:  or which breaks first with the application of energy?
                              Bond Dissociation, kJ/mol
               Energy       Energy, kJ/mol (Handbook Ch & Ph)

  C - C       346              618

  C - H       411              338

  C - S       272              713

By the first column, would think the C- S bond would break first.  By the second
column, BDE, would appear C - H would break first, C - S is the strongest, which is right and why

Title: Re: bond energy vs bond dissociation energy
Post by: AWK on February 16, 2009, 02:29:16 AM

Energy of C-H bonds differs significantly depending on compound and of its substituents.
For C-C and C-s bonds you compare energies of a single bond (left) with energies of a double bond (right)