Question

(a) Calculate the percent ionization of 0.00180 M propionic acid (K_a = 1.3e-05).

% ionization =____________ %



(b) Calculate the percent ionization of 0.00180 M propionic acid in a solution containing 0.0590 M sodium propionate.

% ionization = __________ %

Answer 1

ans--a.---

To calculate the per cent ionization, we need to find out how much of the original acid ionized, and evaluate the ratio

([acid ionized] / [original acid])*100

The equilibrium reaction is

C₂H₅COOH(aq) <===> H⁺(aq) + C₂H₅COO^-(aq)

I 0.00180 0 0

C -x x x

E   0.00180-x x x

so,   Ka = [H=][C3H5O2-] / HC3H5O2]

.3 * 10 ^ -5 = [x][x] / (0.00180 - x)

since ka is 10 to the negativepowe 5, it's small enough that we can ignore the X in 0.00180 - x

x2=0.0054*. 10^-5

x=.000232

% ionization =12.77%