analytical chemisty
posted by mary .
Calculate the pH and pOH of a 0.00002M solution of acetic acid.

Call acetic acid HAc.
............HAc ==> H^+ + Ac^
initial..2E5M......0.......0
change....x........x........x
equil...2E5x......x........x
Ka = (H^+)(Ac^)/(HAc)
Substitute and solve for H^+, then
pH = log(H^+).
Then pH + pOH = pKw = 14
Youknow pH and pKw, solve for pOH.
Note: I think you must solve the quadratic; i.e., you will not be able to make simplifying assumptions.