The concentration of benzoic acid is 0.2 M
Using the ICE Method
HC7H6O2 <=> H+ + C7H6O2-
0.2
-3.55 x 10-3 3.55 x 10-3 3.55 x 10-3
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0.189 3.55 x 10-3 3.55 x 10-3
Ka = (3.55 x 10-3)(3.55 x 10-3)/(0.189)
Ka = 6.67 x 10-5
