One of the most common buffers used in protein chemistry is a
weak base called TRIS (the nitrogen atom of the amino group is the
basic portion of the molecule):
A biochemist prepares a buffer solution by adding enough TRIS
and 12 M HCl to give 1.0 L of a buffer solution that has
concentrations [TRIS] = 0.26 M and [TRISH+] = 0.77 M.
(pKb of TRIS is 5.91.)
(a) Calculate the pH of the buffer solution.
pH =
(b) Suppose that 7.7 mL of 12 M HCl is added to 12 L of the buffer
solution; calculate the new pH of the solution.
pH =