0336 moles of a weak monoproticacid added to a final volume

•0.336 moles of a weak, monoproticacid added to a final volume of 2.00 L exhibits 2.14% ionization. What is the pOH of the solution? 11.56 is the answer please explain steps

Solution

The equation for the dissociation of HA is:

HAc H⁺ + A¯

Molarity = 0.336/2 = 0.168 M

1) Find [H⁺] using the concentration and the percent dissociation:

(0.0214) (0.168) = 3.595 x 10¯³ M

2) pH = -log  [H⁺] = -log (3.595 x 10¯³) = 2.44

3) pH + pOH = 14

pOH = 14 -2.44 = 11.56