## pKa vs Ka

Alexis Robles 2k
Posts: 85
Joined: Wed Sep 18, 2019 12:18 am

### pKa vs Ka

What is the difference between Pka and Ka? Thank you

Justin Ko 4C
Posts: 17
Joined: Mon Sep 23, 2019 12:17 am

### Re: pKa vs Ka

Ka is the acid dissociation constant. Using the formula to calculate pH, we know that p is -log. Therefore, pKa is the -log of the dissociation constant.

Jessica Tejero 3L
Posts: 54
Joined: Wed Sep 25, 2019 12:16 am

### Re: pKa vs Ka

The dissociation constant Ka is usually written as a quotient of the equilibrium concentrations (in mol/L), denoted by [HA], [A−] and [H3O+]. Relationship between Ka, pKa and acid strength: The smaller the value of Ka, the larger the value of pKa, the weaker the acid.

Grecia Velasco 4D
Posts: 56
Joined: Thu Jul 11, 2019 12:17 am

### Re: pKa vs Ka

PKa= -Log[Ka] (for weak acids, log of Ka)

Ka= [A-][H+]/[AH] (acid dissociation constant)

Smalled Ka = larger PKa = weaker acid

Shail Avasthi 3C
Posts: 86
Joined: Fri Aug 30, 2019 12:17 am

### Re: pKa vs Ka

For the following acid equilibrium :

HA <----> H+ + A-

Ka = [H+][A-]/[HA]

pKa = -log[Ka]

Leila_4G
Posts: 96
Joined: Sat Sep 14, 2019 12:17 am

### Re: pKa vs Ka

Ka will always be given, right? We don't have to memorize any of them, right?

Leila_4G
Posts: 96
Joined: Sat Sep 14, 2019 12:17 am

### Re: pKa vs Ka

Ka will always be given, right? We don't have to memorize any of them, right?