In: Chemistry
(a) Calculate the percent ionization of 0.00710 M butanoic acid (Ka = 1.5e-05). % ionization = % (b) Calculate the percent ionization of 0.00710 M butanoic acid in a solution containing 0.0210 M sodium butanoate. % ionization = %
a)
butanoic acid ---------------> butanoate + H+
0.00710 0 0
0.00710 - x x x
Ka = x^2 / 0.00710 - x
1.5 x 10^-5 = x^2 / 0.00710 - x
x = 3.19 x 10^-4
[H+] = 3.19 x 10^-4 M
% ionization = (3.19 x 10^-4 / 0.00710 ) x 100
% ionization = 4.49 %
b)
HA -------------> A- + H+
Ka = [A-][H+] / [HA]
1.5 x 10^-5 = [0.0210][H+] / 0.00710
[H+] = 5.07 x 10^-6 M
% ionization = (5.07 x 10^-6 / 0.0071 ) x 100
% ionization = 0.0714 %