## 9.57 units 6th edition

$\Delta G^{\circ}= \Delta H^{\circ} - T \Delta S^{\circ}$

$\Delta G^{\circ}= -RT\ln K$

$\Delta G^{\circ}= \sum \Delta G_{f}^{\circ}(products) - \sum \Delta G_{f}^{\circ}(reactants)$

Lina Petrossian 1D
Posts: 77
Joined: Fri Oct 05, 2018 12:16 am

### 9.57 units 6th edition

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?

Posts: 37
Joined: Mon Apr 23, 2018 3:00 am

### Re: 9.57 units 6th edition

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.

Lina Petrossian 1D
Posts: 77
Joined: Fri Oct 05, 2018 12:16 am

### Re: 9.57 units 6th edition

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??