Ka. Kb, Kw

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Baoying Li 1B
Posts: 113
Joined: Sat Aug 17, 2019 12:18 am

Ka. Kb, Kw

Postby Baoying Li 1B » Sat Dec 07, 2019 8:37 pm

What is the difference between Ka, Kb, and Kw?
Also, what is the difference between Ka1 and Ka2?
Do we need to calculate Ka and Kb in the final?

Brian J Cheng 1I
Posts: 115
Joined: Thu Jul 11, 2019 12:15 am

Re: Ka. Kb, Kw

Postby Brian J Cheng 1I » Sat Dec 07, 2019 8:47 pm

What is the difference between Ka, Kb, and Kw?
Also, what is the difference between Ka1 and Ka2?
Do we need to calculate Ka and Kb in the final?

Ka * Kb = Kw = 1.0 x 10^-14
pKa + pKb = pKw = 14

Ka1 and Ka2 only appear in polyprotic acids (i.e. H2so4). Ka1 is the dissociation constant when 0 H+ are lost, and Ka2 is the disc. when one H+ is lost.

Dr. Lavelle has mentioned we won't need to know how to calculate Ka and Kb extensively, but remember that strong acids and bases dissociate completely and try and think about how this will affect the Ka/Kb.

Dan M -3E
Posts: 101
Joined: Wed Sep 18, 2019 12:19 am

Re: Ka. Kb, Kw

Postby Dan M -3E » Sat Dec 07, 2019 9:19 pm

For strong acids, you just calculate pH, not Ka or Kb.

Ka is equal to the concentration of the products divided by the concentration of the reactants, so unless you are given those, you won't have to calculate it. Then, finding pKa is the negative log of it. pKa + pKb = 14

AveryAgosto
Posts: 76
Joined: Wed Sep 18, 2019 12:16 am

Re: Ka. Kb, Kw

Postby AveryAgosto » Sat Dec 07, 2019 9:20 pm

Ka refers to the pH formula and Kb refers to the pOH formula. Kw is a constant.

Oduwole 1E
Posts: 100
Joined: Fri Aug 02, 2019 12:16 am

Re: Ka. Kb, Kw

Postby Oduwole 1E » Sun Dec 08, 2019 6:34 pm

Ka has to do with acids (pH), Kb has to do with bases (pOH), and Kw is a constant.


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