## Why is Kw value typically used at 25 degrees C [ENDORSED]

Acidity $K_{a}$
Basicity $K_{b}$
The Conjugate Seesaw $K_{a}\times K_{b}=K_{w}$

Moderators: Chem_Mod, Chem_Admin

peytonruiz 1H
Posts: 20
Joined: Fri Sep 29, 2017 7:03 am
Been upvoted: 1 time

### Why is Kw value typically used at 25 degrees C

Why is it standard to use the value for Kw at 25 degrees C?

Maeve Gallagher 1J
Posts: 56
Joined: Fri Sep 29, 2017 7:07 am

### Re: Why is Kw value typically used at 25 degrees C

25 degrees Celsius is the standard room temperature value used for most equations and calculations in chemistry. It is just used to show that its not super hot or super cold.

Yizhou Liu 3L
Posts: 19
Joined: Fri Sep 29, 2017 7:07 am

### Re: Why is Kw value typically used at 25 degrees C

Because 25 degrees C is the room temperature. If the temperature increase, the Kw will increase as well.

Wayland Leung
Posts: 51
Joined: Sat Jul 22, 2017 3:00 am
Been upvoted: 1 time

### Re: Why is Kw value typically used at 25 degrees C

Does only changing the temperature affect the Kw value? Does anything else affect the Kw value?

Dylan Davisson 2B
Posts: 50
Joined: Thu Jul 27, 2017 3:00 am
Been upvoted: 2 times

### Re: Why is Kw value typically used at 25 degrees C

Because kW is the equilibrium constant, it only changes with temperature. This is because the dissociation of water molecules is an endothermic process, a process that is affected by temperature. The higher the temperature, the further the equilibrium moves to the right, which affects the kW value.

diangelosoriano
Posts: 49
Joined: Fri Sep 29, 2017 7:07 am

### Re: Why is Kw value typically used at 25 degrees C

Will we be expected to be able to calculate at different temperatures for the final?

Chem_Mod
Posts: 19170
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 833 times

### Re: Why is Kw value typically used at 25 degrees C  [ENDORSED]

diangelosoriano wrote:Will we be expected to be able to calculate at different temperatures for the final?

Chem 14A, no.

I will cover this in Chem 14B when we do thermodynamics.

Return to “Acidity & Basicity Constants and The Conjugate Seesaw”

### Who is online

Users browsing this forum: No registered users and 0 guests