### Question 13.33

Posted:

**Tue Aug 01, 2017 5:13 pm**"Suppose that 4.25 g of an unknown monophonic acid weak acid, HA, is dissolved in water. Titration of the solution with 0.350 M NaOH(aq) required 52.0 mL to reach the stoichiometric point. After the addition of 26.0 mL, the pH of the solution was found to be 3.82. (a) What is the molar mass of the acid? (b) What is the value of pKa for the acid?"

I have figured out (a), but I am having trouble with (b). I'm not sure how to solve for this. Could someone please explain this to me? Thanks!

I have figured out (a), but I am having trouble with (b). I'm not sure how to solve for this. Could someone please explain this to me? Thanks!