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### 9.57 units 6th edition

Posted: Tue Feb 19, 2019 7:51 pm
9.57 Calculate the standard reaction entropy, enthalpy, and Gibbs free energy for each of the following reactions from data in Appendix 2A:
(a) the decomposition of hydrogen peroxide:
2 H2O2(l) -> 2 H2O(l) + O2(g)

Why is the answer for delta H in the textbook kj per mole when the reaction is not decomposing one mole but rather 2 moles?

### Re: 9.57 units 6th edition

Posted: Tue Feb 19, 2019 7:55 pm
The calculations for deltaH consider the amount of moles when you multiply the deltaHf by the respective stoichiometric coefficients. So in this case, you would multiply the deltaHf of H2O2 by 2 to account for the fact that the reaction is decomposing 2 moles of H2O2. The end result is kJ/mol.

### Re: 9.57 units 6th edition

Posted: Tue Feb 19, 2019 8:02 pm
Hi unfortunately I am still confused. The answer -196.10 kj per mole is actually per 2 moles of H2O2 decomposed. Therefore, shouldnt the answer be half of that in order to get per mole decomposed??