## Quiz 1 Preparation, Winter 2014, #9 and #12

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

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

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

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### Quiz 1 Preparation, Winter 2014, #9 and #12

Question 9 asks to calculate delta G for the balanced reaction. I obtained the correct numerical value, but my answer is in units of kJ instead of kJ/mol as the workbook's answer states. I have noticed this happening in several other calculations, but I thought that the moles canceled when you multiplied by the number of moles in the chemical equation. For example, question 12 requires you to find delta H and delta S, but the answers are all in units of kJ/mol. Could someone please explain this to me?

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### Re: Quiz 1 Preparation, Winter 2014, #9 and #12

The units for those situations should be KJ or J for deltaG or deltaH

and KJ/K or J/K for deltaS

Unless they are asking you to find the entropy of vaporization for a general process for example (9.19 in the text).

Some of the solution manual units are off, but refer to the course reader or textbook examples for correct use of units.

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