hi i need help and currently pursuing my bsc I need help in a question.


Question
Determine the % ionisation of ibuprofen in blood(ph 7.4).
The pka of thiol group in of an active site cysteine residue if determined to be 8.5. Determine the ratio of
protonated(thiol) to deprotonated (thiolate) groups at pH 7.

Would sincerely appreciate your help.

Regards
Shanti

Hi Shanti
use    Henderson–Hasselbalch equation
pH =pKa - log[deprotonated thiol ]/[protonated thiol]