Suppose you want to prepare a buffer solution having a pH of about 9.3. Describe how you would prepare the buffer solution using one of the weak bases listed in the Table below and any other necessary reagents.

base                                        Kb
methylamine (CH3NH2)             4.4 x 10-4
ethanolamine (HOCH2CH2NH2)   3.2 x 10-5
ammonia (NH3)                       1.8 x 10-5
pyridine (C5H5N)                     1.7 x 10-9