[mandy9008]

The AIDS drug zalcitabine (also known as ddC) is a weak base with a pKb of 9.8.

What percentage of the base is protonated in an aqueous zalcitabine solution containing 550 mg/mL

i know what protonated is another term for % ionization.
i assume that i must put the pKb into Kb, then solve with the molarity. i know that i must convert the solution into M, which is 2.60 mol/L.
i have no clue on what to do next.

[Borek]

http://www.titrations.info/acid-base-titration-indicators

Page is about something else, but at the very beginning of the page you will find an interesting equation that you can use.