Consider the diprotic acid mercaptoacetic acid, where the fully protonated form can be denoted by H2A. Calculate the pH of the solutions below.
a) 0.0500 M of mercaptoacetic acid, H2A
b) 0.0500 M the sodium salt, NaHA
c) 0.0500 M disodium salt, Na2A
For the solution in Part 5(c), what are the concentrations of A2-, HA-, and H2A?