Question

Where did you get 5E-5.
Is this how you set it up?
0.01 x 0.05 = 5E-4
If so, is it supposed to be 5E-4 instead of 5E-5?

What is the equilibrium constant for a weak acid HA that dissociates 1% at an initial concentration of 0.05 M according to the following balanced chemical equation?

HA <----> H+ + A-
Chemistry- DrBob222 - DrBob222, Saturday, March 12, 2016 at 11:03pm
........HA <----> H+ + A-
I.....0.05........0.....0
C....-5E-5........5E-5..5E-5
E......?..........5E-5..5E-5

Substitute the E line (after evaluation 0.05-5E-5) and solve for Ka.