Percent ionization vs protonation

[Brenda Tran 3C]

Hello!

Is there a difference between percent ionization and percent protonation? If so, what is it?

[Quynhanh Nguyen 1C]

Hi! I believe protonation refers to the addition of protons to a species whereas ionization refers to the changing of electrons. However, for the purposes of acids and bases, when we're asked to calculate the percentage ionization or percentage protonation, it is the same. Hope that helps!

[Arya Bhalla 1H]

Percent protonation is used when we are dealing with reactions involving weak bases while percent ionization (or deprotonation) is used when we are dealing with reactions involving weak acids.

Easy way to remember:
Protonation refers to weak bases because they gain H+ (proton)
Deprotonation (ionization) refers to weak acids because they lose H+ (a proton is lost)

[Morgan Oey-3H]

There is also a slight difference when calculating them.

For % ionized/deprotonated, you use calculate as following: [A-] / [HA]initial x 100%.

For % protonated, you use [BH+] / [B]formal x 100%. [B]formal is just [B]+[BH+].