pKa vs Ka

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Alexis Robles 2k
Posts: 100
Joined: Wed Sep 18, 2019 12:18 am

pKa vs Ka

Postby Alexis Robles 2k » Mon Dec 02, 2019 9:48 pm

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

Postby Justin Ko 4C » Mon Dec 02, 2019 9:55 pm

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

Postby Jessica Tejero 3L » Mon Dec 02, 2019 9:58 pm

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

Postby Grecia Velasco 4D » Mon Dec 02, 2019 10:10 pm

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

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

Smalled Ka = larger PKa = weaker acid

Shail Avasthi 2C
Posts: 101
Joined: Fri Aug 30, 2019 12:17 am

Re: pKa vs Ka

Postby Shail Avasthi 2C » Tue Dec 03, 2019 7:53 pm

For the following acid equilibrium :

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

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

pKa = -log[Ka]

Leila_4G
Posts: 114
Joined: Sat Sep 14, 2019 12:17 am

Re: pKa vs Ka

Postby Leila_4G » Tue Dec 03, 2019 9:03 pm

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

Leila_4G
Posts: 114
Joined: Sat Sep 14, 2019 12:17 am

Re: pKa vs Ka

Postby Leila_4G » Tue Dec 03, 2019 9:04 pm

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


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