Calculate the pH during the titration of 10.00 mL of 0.400 M hypochlorous acid with 0.500 M NaOH.

The Ka for HOCl is 3.0 x 10-8 M.

What is the pH at the equivalence point?

I used the HH formula and got pH=7.52+log(.222)=6.87, but its not right.

The pH at the equivalence point is determined by the hydrolysis of the salt (you don't have an acid and a base at the equivalence point so you can't use the HH equation). You can calculate the concn of the salt at the eq point but let's call it z.

...........ClO^- + HOH ==> HClO + OH^-
I..........z.................0.....0
C..........-x................x.....x
E..........z-x...............x.....x

Kb for ClO^- = (Kw/Ka for HClO) =
(x)(x)/(z-x). Solve for x = (OH^-) and convert to pH.