Prepare 250 ml of a phosphate-buffered saline solution (pbs) containing 0.138 m nacl, 0.0027 m kcl, 0.01 m phosphate using the correct amounts of sodium dihydrogen phosphate and disodium hydrogen phosphate to produce a solution with a ph of 7.4.
2) after you have calibrated your ph meter, measure and record the ph of the solution. if the ph is not 7.4, adjust the ph to 7.4 with either hcl or naoh. record the number of drops of naoh needed to bring the ph to 7.4.
3) bring the solution to final volume using a volumetric flask.
part b (group 2):
4) prepare 250 ml of a phosphate-buffered saline solution (pbs) containing 0.138 m nacl, 0.0027 m kcl, 0.01 m phosphate using sodium dihydrogen phosphate as the source of phosphate.
note: do not fill you volumetric flask completely to the 250 ml line, since you still need to add naoh to adjust ph.
5) measure and record the ph of the solution.
6) adjust the ph of the solution to 7.4 using 3.4 m naoh. record the number of drops of naoh needed to bring the ph to 7.4.
7) bring the solution to final volume of 250 ml using a volumetric flask.

question is

what percent of the conjugate acid is ionized at this ph?