# Chemical Forums

## Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: liravsc on November 16, 2021, 06:40:23 PM

Title: Reason between protonated and deprotonated bases
Post by: liravsc on November 16, 2021, 06:40:23 PM
"An acid with a pKa of 8 is present in a solution of pH 6. What's the reason between the protonated and deprotonated bases?"

I'm probably completely wrong, but I tried Handerson-Hasselbach's equation here. Got stuck at $$\frac {log[A-]}{log[HA]} = -2$$. I can't think of anything else how to calculate this. Thank you!
Title: Re: Reason between protonated and deprotonated bases
Post by: Borek on November 17, 2021, 02:55:43 AM
Reason or ratio?

But yes, HH equation is the way to go.
Title: Re: Reason between protonated and deprotonated bases
Post by: sjb on November 17, 2021, 03:18:32 AM
More like $$log \frac {[A-]}{[HA]} = -2$$

Can you find another equation relating [A-] and [HA]?
Title: Re: Reason between protonated and deprotonated bases
Post by: liravsc on November 17, 2021, 08:29:50 AM
Reason or ratio?

But yes, HH equation is the way to go.

haha ratio! Sorry I'm translating from portuguese

EDIT: figured it out, since the difference between the pH and pKa is -2, the ratio is 10-2. Is that correct?