Question about using mean bond enthalpies to estimate the enthalpy of a reaction

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Alex_Wagas_3K
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Question about using mean bond enthalpies to estimate the enthalpy of a reaction

Postby Alex_Wagas_3K » Sat Jan 14, 2017 2:38 pm

One of the textbook questions list the following:

Use bond enthalpies to estimate the standard enthalphy of the reaction...
CCl3CHCl2 (g) + 2 HF (g) ---> CCl3CHF2 (g) + 2 HCl (g)

The answer the the question is -24 kJ/mol, but when I try and calculate it on my own I keep getting -30 kJ/mol.

I would just like to verify which bonds are breaking and which ones are forming.

I presume C--Cl and H--F are breaking and C--F and H--Cl are forming.

Any help would be appreciated. Thank you!

Chem_Mod
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Re: Question about using mean bond enthalpies to estimate the enthalpy of a reaction

Postby Chem_Mod » Sat Jan 14, 2017 3:38 pm

If you can list the bond enthalpy values and the math you are doing, it would greatly help me figure out what is going wrong.


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