Ok, well I'm guessing I have to use the Henderson-Hasselblach equation because of the information I'm given and I have to solve for pKa from the equation. So the equation is going to be...
8.44 = pKa + log([conjugate base]/[acid])
I'm having trouble figuring out what values should be used for the conjugate base and acid concentrations. I know you use the NaOH and HA somehow, but that's where I'm stuck.