Ch 8 #57

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Ch 8 #57

Postby Maria1E » Thu Jan 11, 2018 9:50 pm

Why does the solution manual state the final units for this problem as kJ/mol, even though the units given for delta H in all other problems on reaction enthalpies (such as #61) are kJ? Are the final units for delta H in reaction enthalpy problems kJ/mol or kJ?

Brandon Fujii 1K
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Re: Ch 8 #57

Postby Brandon Fujii 1K » Thu Jan 11, 2018 10:28 pm

In 8.57 each individual enthalpy value is given in kJ/mol. Thus, I believe that the question is asking us to solve for the enthalpy for the hydrogenation of 1 mole of ethane. 8.61 gives each individual enthalpy value in kJ (possibly because it is not solving for the enthalpy of 1 mole of Bromide Gas.) I hope that this helps.

Gevork 2E
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Re: Ch 8 #57

Postby Gevork 2E » Thu Jan 11, 2018 10:33 pm

I think it might have to do with it being a reaction, so it is probably referring to the idea that you would react one mol of reactants in that theoretical reaction.

This might not be the case, but that's how I had understood it.

As far as what units needs to be used, it would depend on the context of the question, as seen with this particular question.

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