## pKa and Ka

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

Valeria Viera 1B
Posts: 60
Joined: Fri Apr 06, 2018 11:05 am

### pKa and Ka

In problem 12.35 (6th Ed) they ask us to get Ka from pKa which is fine you just use 10^pKa. However I noticed that the pKa values have numbers right next to them like pKa1=... or pKa2=....
what do they mean by saying pKa2 ? How do you get Ka from that ?

(Part d says: give the Ka value for the acid H2SeO4-, pKa2= 1.92 )

Arshiya
Posts: 69
Joined: Fri Sep 28, 2018 12:16 am
Been upvoted: 1 time

### Re: pKa and Ka

Because polyprotic compounds can dissociate multiple times, there will be multiple pKa values for every reaction that occurs. Depending on the information given in the question u will be able to find Ka for a given step.