Calculate the percentage of HOAc molecules?

Calculate the percentage of HOAc molecules that dissociate in a 0.0100 M solution of acetic acid (HOAc). For HOAc, Ka = 1.8e-5.Calculate the percentage of HOAc molecules?
Using ICE (initial, change, equilibrium) table:



---HOAC = H+ + OAC-

I---0.010

C---(-x)----(+x)------(+x)

E--(0.010-x)--x--------x



Ka = [H+][OAC-]/[HOAC] = 1.8 x 10^-5

(x)*(x)/(0.010 - x) = 1.8 x 10^-5



Since [HOAC]/Ka %26gt; 100, we can simplify the above equation to:



x^2/0.010 = 1.8 x 10^-5

x = 4.24 x 10^-4 = [H+]



% dissociation = [H+]/[HOAC] x 100%

% dissociation = 4.24 x 10^-4/0.0100 x 100% = 4.2%



That's it!n_nCalculate the percentage of HOAc molecules?
1.8 x 10^-5 = x^2 /0.0100-x

x =0.000424

% = 0.000424 x 100/ 0.0100=4.24