## Van't Hoff Equation

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

Jeffrey Wang
Posts: 18
Joined: Fri Sep 25, 2015 3:00 am

### Van't Hoff Equation

I don't quite understand when and why I need to use this equation. What is its relevance to delta H? What is an example of the problem that utilizes this?

Austin Hyun 1F
Posts: 26
Joined: Fri Sep 25, 2015 3:00 am

### Re: Van't Hoff Equation

So essentially, the Van't Hoff Equation is used to calculate the equilibrium constant at different temperatures. The equation assumes a constant delta So and a constant delta Ho, as these standard values should not change based upon a temperature change. Thus, given K1 at temperature T1, you can use the Van't Hoff Equation to calculate K2 at any temperature T2 for a reaction. I hope that clarifies things!

Rachel Lipman
Posts: 45
Joined: Fri Sep 25, 2015 3:00 am

### Re: Van't Hoff Equation

What type of wording in a question would lead us to use this equation?

Caleb Lim 2M
Posts: 13
Joined: Wed Sep 21, 2016 2:55 pm

### Re: Van't Hoff Equation

Is the Van`t Hoff Equation related to the Arrhenius Equation, or am I totally off the mark? I remember seeing that equation but I thought it was the Arrhenius equation (A variataion or something of it).

EmmaSaid3C
Posts: 22
Joined: Fri Jul 22, 2016 3:00 am

### Re: Van't Hoff Equation

I think that the best way to know when to use the Van't Hoff Equation is when you are given 2 equilibrium reactions at two different temperatures. It is part of the thermodynamics chapter and can be found on page 42 in the course reader.

Irma Ramos 2I
Posts: 51
Joined: Fri Sep 29, 2017 7:07 am

### Re: Van't Hoff Equation

Would there ever be a time when we are asked to calculate K but not given delta H? If so, then how would we solve for K?