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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: butters on December 14, 2010, 09:46:07 PM

Title: The compound difluoride is quite reactive. It produces oxygen and HF(g) when tre
Post by: butters on December 14, 2010, 09:46:07 PM

The compound oxygen difluoride is quite reactive, giving oxygen and HF when treated with water:

OF2(g) + H2O(g) --> O2(g) + 2 HF (g) ΔH°rxn = -318 kj/mole

Using bond energies, calculate the bond dissociation energy of the O-F bond in OF2(g).

According to someone on Yahoo Answers, this is how to solve it: -318 kJ/mol = BDE for OF2 + BDE for H2O - BDE for O2 - 2 x BDE for HF.

But the Bond Diassociation Energy (BDE) chart in my book has a blank space for O-F. So then how do I solve this, there must be a different method.

The answer to this question is -126kj.
Show me how to solve this..

Title: Re: The compound difluoride is quite reactive. It produces oxygen and HF(g) when tre
Post by: butters on December 15, 2010, 02:18:09 AM

Oops, the actual answer is 192kj/mol not 126.
Sorry about that. 

Title: Re: The compound difluoride is quite reactive. It produces oxygen and HF(g) when tre
Post by: saden99 on December 16, 2010, 02:39:52 AM

The person on Yahoo answers is correct. Was trying to solve it myself and didn't come up with anything close to -192kj/mol...


I'm not sure if my table of dissociation energies is radically different or if they are using an odd # for the dissociation of the water.