have available .1 (N) NaOH and .1 solutions N solutions of H2SO4, acetic acid (pk=4.76), lactic acid (pK=3.86), and phosphate (pK=7.2) and ammonium chloride (pK=p.25).

a) Assuming the various solutions are used without dilution with water,how would you prepare 50ml of a buffered medium to keep pH essentially constant at 5.40 in an enzyme experimement in which acid will be produced?

b) If .1 milliequvalent of acid id produced in 50ml reaction mixture by the enzymatic reaction, what will be the final pH of the solution?