# Calculate the percent ionization of a 0.15 formic acid solution in a solution containing 0.11 potassium formate.

I have the formic acid Ka=1.8 *10^-4

When I solve for "x" I'm getting 1.1.44*10^-2 When I plug that into equation (x/0.15-x)*100, I'm getting 10.6% which is incorrect. I getting lost in the math, plz help. Thanks