The equations and constants for the dissociation of three different acids are given below. HCO3- ? H+ + CO32- Ka = 4.2e-7 H2PO4- ? H+ + HPO42- Ka = 6.2e-8 HSO4- ? H+ + SO42- Ka = 1.3e-2 1. From the systems above, identify the conjugate pair that is best for preparing a buffer with a pH of 7.2. Explain your choice. 2. Explain briefly how you would prepare the buffer solution described in (a) with the conjugate pair you have chosen. 3. If the concentrations of both the acid and the conjugate base you have chosen were doubled, how would the pH be affected? Explain how the capacity of the buffer is affected by this change in concentrations of acid and base. 4. Explain briefly how you could prepare the buffer solution in (a) if you had available the solid salt of the only one member of the conjugate pair and solution of a strong acid and a strong base.