You work in a medical research lab with a biochemist who asks
you to make a 1.00 L phosphate buffer stock solution with pH = 7.4.
The total phosphorus concentration is to be 0.250 M. In the
storeroom, there are the following reagents: (1) a 3.00 M
phosphoric acid stock solution, (2) solid sodium dihydrogen
phosphate, (3) solid sodium monohydrogen phosphate, (4) solid,
sodium phosphate, (5) a 3.00 M HCl(aq) stock solution, (6) a 3.00 M
NaOH(aq) stock solution, and...