January 23, 2021, 10:21:23 PM
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### Topic: How to calculate ∆rGº from entropy and ∆fGº in different temperatures?  (Read 147 times)

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#### iago_maciel

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• Mole Snacks: +0/-0 ##### How to calculate ∆rGº from entropy and ∆fGº in different temperatures?
« on: December 15, 2020, 04:38:40 PM »
"The total oxidation of glucose occurs according to the following chemical equation:

C6H12O6 (s) + 6O2 (g) -> 6CO2 (g) + 6H2O (l)

The table gives us the free energies of standard formation and the standard molar entropies of compounds involved in the previous reaction.

| Compound |  ∆fG° (298K) kJ/mol | S°m (298K) J/K/mol |
|-------------|-------------------------|------------------------|
|C6H12O6   |            -917,2           |           212,10          |
|     O2        |               0               |            205,14         |
|     CO2      |          -394,36           |            213,74         |
|      H2O     |           -273,13          |            69,91           |

Based on the table data, determine the ∆rGº for glucose oxidation at 308 K"

Guiven:

R = 8,314 J K-1 mol-1

∆rG = ∆rG°+RT 𝑙𝑛 Q

ln 𝐾2 = ln 𝐾1 −∆rH°/ 𝑅 (1/𝑇1−1/𝑇2)

I calculated ∆rH° and I want to know if I need to use any of the guiven formula or if i can use ∆rG = ∆rH - T∆rS to calculate ∆rG considering ∆rH and ∆rS as constant.