## Van't Hoff Equation

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

Aiden Metzner 2C
Posts: 104
Joined: Wed Sep 18, 2019 12:21 am

### Van't Hoff Equation

I'm not sure when we apply this equation. Can someone explain to me what types of problems we use this equation for?

Ally Huang- 1F
Posts: 103
Joined: Thu Jul 25, 2019 12:16 am

### Re: Van't Hoff Equation

You use the Van't Hoff equation when trying to find K, an equilibrium constant, at a different temperature. Delta H at standard temperature and pressure must be known in order to use this equation, but this equation allows us to see temperature dependence of K.

KaleenaJezycki_1I
Posts: 127
Joined: Sat Aug 17, 2019 12:18 am
Been upvoted: 2 times

### Re: Van't Hoff Equation

This is used to display the temperature dependence of K, so it is used when calculating K at different temperatures and can even be used when the question is asking for what the pH is at different temp when given an initial K value. I don't think this is derived for us on the constant sheet so it's good to understand.

Abigail Sanders 1E
Posts: 112
Joined: Wed Sep 11, 2019 12:16 am

### Re: Van't Hoff Equation

This equation also allows us to compare two K values K1 and K2 and observe how the change in temperature either increases or decreases K. The equation for comparing is: ln (k2/k1) = -(delta*H)/R * (1/T1 - 1/T2) . However, as stated above, the Van't Hoff Equation's purpose is to show the temperature dependence of K.