7. How many moles of OH are required to raise the pH of 4.00 liters of 25 mM glycine, pH 1.90, to a final pH of 9.70? Assume that the addition of OH does not change the volume of the solution. The pKa's of glycine are a-COOH group 2.34 and a-NH3+ group 9.60. 0.129 mol OH You will need two H-H calculations, one for pH 1.90 and the pKa of 2.34 and the other for pH 9.70 and the pKa of 9.60. The challenge is to know whether to pay attention to the "b" or the "a" in each calculation. Also note that you are moving moles of groups up the titration curve.