chemistry
posted by Lisa, Help needed! .
I have no clue, please help and explain! =)
Find the pH of a 0.150 M solution of a weak monoprotic acid having Ka=1.2×10−5.
Find the percent dissociation of this solution.
Find the pH of a 0.150 M solution of a weak monoprotic acid having Ka=1.4×10−3.
Find the percent dissociation of this solution.
Find the pH of a 0.150 solution of a weak monoprotic acid having Ka= 0.11.
Find the percent dissociation of this solution.

I need help =(

and thank you!