Using activity coefficients, calculate the pH of a solution containing a 3.00:1.00 mole ratio of HC$^2$-:C$^3$- (H$_3$C = citric acid).
The ionic strength is 0.010 M. The $pK_a$ values for citric acid are 3.13, 4.76, and 6.40.
pH =
What will be the pH if the ionic strength is raised to 0.10 M and the mole ratio HC$^2$-:C$^3$- is kept constant?
pH =