## 11.116

$\ln K = -\frac{\Delta H^{\circ}}{RT} + \frac{\Delta S^{\circ}}{R}$

Ju-Wei Wang 1I
Posts: 31
Joined: Fri Sep 29, 2017 7:05 am

### 11.116

During discussion, we did this practice problem by using Van't Hoff's equation and the relationship between ∆G = -RTlnK = ∆H - T∆S. We didn't write out all the steps, so I'm a little confused on how to solve for the first K value that would be subsequently substituted into Van't Hoff's equation. Can someone explain how to obtain that value given the temperature of 37 degrees celcius,the standard change in enthalpy of the reaction is -20 kJ/mol, and the standard change in entropy of the reaction is +34 J/K.mol?

sahiltelang-Discussion 1J
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

### Re: 11.116

You can use entropy, enthalpy and temperature to calculate deltaG and then use this value to find the original K using deltaG=-RTln(K). Once K1 is calculated then you can use the Van Hoff equation.

Krupa Prajapati
Posts: 50
Joined: Sat Jul 22, 2017 3:00 am

### Re: 11.116

Hi. To add onto that, the explicit equation we can use is lnK = (delta G)/(-RT) or e^((delta G)/(-RT)). We can then find this answer and plug it into the Van't Hoff's Equation.