## 11.83

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

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

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

veneziaramirez 3I
Posts: 57
Joined: Fri Sep 29, 2017 7:07 am

### 11.83

Why do we need to find delta S?

Jason Liu 1C
Posts: 52
Joined: Fri Sep 29, 2017 7:04 am

### Re: 11.83

We are looking for K, which can be found with the equation ΔG = -RTlnK. So first we need to find ΔG. We can do that by using the equation ΔG = ΔH - TΔS. We are given the temperature, but we still need to find ΔH and ΔS in order to find ΔG.

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

### Re: 11.83

For 11.83, we need to find both delta H and delta S in order to use the formula delta G = delta H - T delta S to find delta G. We are not given the delta G, so we would need to find this. Once you find delta G, you can just use the formula delta G = -RTlnK to find K, the equilibrium constant.

Lindsay H 2B
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am
Been upvoted: 1 time

### Re: 11.83

Why do we need to find ∆G by using ∆H-T∆S instead of by using ∑∆G(products)-∑∆G(reactants)? I tried this with the ∆G values in the appendix but I got a different answer

Aya Shokair- Dis 2H
Posts: 58
Joined: Fri Sep 29, 2017 7:07 am

### Re: 11.83

^^ Yes! So did I, would it be wrong to use ∑∆G(products)-∑∆G(reactants)?