## Arithmetic in 11.19c

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

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

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

Lucia H 2L
Posts: 43
Joined: Mon Nov 14, 2016 3:00 am
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### Arithmetic in 11.19c

Can someone please show the math they did in 11.19c?

Calculate k for CaCO3(s) --> CaO(s) + CO2(g) at 25 degrees C

k = 1x10^-23 but my calculator keeps rounding to zero and I want to see if I did it right.

Thanks.

Andres Reynoso 1J
Posts: 30
Joined: Fri Sep 29, 2017 7:06 am

### Re: Arithmetic in 11.19c

http://i1380.photobucket.com/albums/ah165/andresreynoso/chemcomm_zps6ilqogyd.jpg
Hopefully this helps!

*Edit: Photobucket doesn't allow third party hosting, so I just submitted the direct link.
Last edited by Andres Reynoso 1J on Sat Feb 24, 2018 8:50 pm, edited 2 times in total.

Posts: 88
Joined: Fri Sep 29, 2017 7:03 am

### Re: Arithmetic in 11.19c

delta G = (-604.03 - 392.36) + 1128.8 = 130.41 kj/mol
lnk = - 130410/(8.314*298.15) = -52.61
k = e^(-52.61)
k = 1.419 * 10^-23
k = 1 * 10^-23
Hopefully this helps!