The drug is a weak acid and has a molecular weight of 356 and a pK of 2.76. The drug is dissolved in isotonic NaC1 solution (0.9 g NaC1 per 100 mL) to make a 3% w/v solution. 

What is the pH of this solution (disregarding activity)?

What the pH of this solution using ionic activity coefficients? (recall the Debye-Huckel equation).