How much of each stock would you need for 100 ml of buffer?

Apr 2018
1
0
Australia
I don't really know how to do this question - please help!

You are running a biochemical assay with an enzyme that needs to maintain a constant pH of 6.6 in order to operate effectively. Using starting stock solutions of 0.2M of NaH2PO4 and Na2HPO4, how much of each stock would you need for 100 ml of buffer at a final concentration of 0.01M and a pH of 6.6.

Hint: First calculate the dilution to determine total amount of phosphate stock required. Then use the Henderson-Hasselbalch equation to calculate the ratio of acid to base.