pKa and pKb

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

Tara_Hekmati_3B
Posts: 28
Joined: Wed Sep 21, 2016 2:59 pm

pKa and pKb

Are pKa and pKb measured on a scale of 0 to 14?

Also, does smaller pKb indicate a more basic base and the same for an acid with its pKa?

Thanks

Tiffany_Hoang_3C
Posts: 20
Joined: Wed Sep 21, 2016 2:59 pm

Re: pKa and pKb

Yes, you are correct! pKA and pKB are measured on a scale of 0 to 14 since pKA=-logKA and pKB=-logKB.

A smaller pKB does indicate a stronger base and a smaller pKA does indicate a stronger acid.

Sarah_Heesacker_3B
Posts: 21
Joined: Wed Sep 21, 2016 2:57 pm

Re: pKa and pKb

Also, the reason it is from 0 to 14 is because pKa + pKb = pKw. pKw is -log(Kw)= -log(10-14)= 14.