you want a solution that will buffer the addition of either 10 micro moles of acid or 10 micro moles of base. total buffer concentration is equal to the concentration of the acid plus the concentration of salt in the acid. which of the following buffers would you use if you wanted to buffer a solution at pH=6.9?
a. buffer A with a pKa of 7.5 and a buffer concentration of 10 nanomolar
b. buffer B with a pKa of 6.6 and a buffer concentration of 10 micromolar
c. buffer C with a pKa of 7.9 and a buffer concentration of 10 micromolar
d. buffer D with a pKa of 6.6 and a buffer concentration of 100 micromolar
e. buffer A with a pKa of 7.4 and a buffer concentration of 100 micromolar