An experimenter has three solutions: 14.5mmol HCHO2, 8.5mmol of NaHCOO, and 0.75 mmol KOH

A what is the pH of a 90 mL solution of .50 mmol of KOH,

B what is the pH of a 75 mL solution of 8.5 mmol of NaHCOO, [Kb(HCOO-)=5.5*10^-11]

C what is the pH of a 75 mL solution of 14.5 mmol of HCHO2 and 8.5 mmol of NaHCOO , [pKa(HCOOH)=3.74]

D What is the pH of the solution in part D when 0.75 mmol of KOH is added(assume no volume change)