Question

calculate the percent ionization of a 0.600 M solution of the monoprotic acetylsalicyclic acid (aspirin). (ka=3.0 x10 ^-4)

Answer 1

Solution:-

Since the acid is monoprotic so we could simply represent it by HA. Weac acids and bases do not ionize completely so we make the ICE table for them to find out the percent ionization.

HA <------------> H+ + A-

I 0.600 0 0

C -X +X +X

E (0.600 - X) X X

Ka = [H+] [A-]/[HA]

3.0 x 10^-4 = (X)^2/(0.600 - X)

on cross multiply...

0.00018 - 0.0003X = X^2

X^2 + 0.0003X - 0.00018 = 0

It's a quadratic equtaion that could be solved for X. on solving this...

X = 0.0133

Percent ionization = (X/C)*100 = (0.0133/0.600)*100 = 2.22%

So, the percent ionization of the acid is 2.22% (Answer)