## Problem 12.45 (6th edition)

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

pamcoronel1H
Posts: 45
Joined: Fri Sep 28, 2018 12:25 am

### Problem 12.45 (6th edition)

I am confused about the pattern of strength described in the solution. In my lecture notes I have it that the stronger the acid, the weaker it conjugate base, so that would be that a higher pKa would mean a lower kb and therefore a weaker conjugate base, right?

The solutions manual says that the stronger the pKa the stronger the conjugate base, so now I am confused on which pattern is right. Could someone explain the relationship between pKa and the strength of its conjugate base?

Thanks!

(By the way, for my answer I put d>a>b>c, which was the complete opposite of the answer)

Eshwar Venkat 1F
Posts: 32
Joined: Fri Sep 28, 2018 12:22 am

### Re: Problem 12.45 (6th edition)

The trend is that the higher the pKa value, the weaker the acid, and the stronger the base, the weaker its conjugate acid will be. As a result, the base strengths for this problem correspond to the increasing pKa values for the conjugate acids.

Vicky Lu 1L
Posts: 60
Joined: Fri Sep 28, 2018 12:18 am

### Re: Problem 12.45 (6th edition)

The trend is that the a smaller pKa/larger the Ka, the stronger the acid and the larger the pKb/smaller the Kb, the stronger the acid. Likewise, the smaller the pKb/larger the Kb, the stronger the base and the larger the pKA/smaller Ka, the stronger the base.