you need to make 500ml of 100mM potassium phosphate buffer at pH7.5.You have the
 

stock solutionsKH2PO4 &K2hpo4? at 1M ea. You will make a buffer by adding some of each of these solutions to water. How many mls of the KH2PO4 stock solution will you use? pKa values for phosphate are 2.12, 7.21, 12.3. Answer should be round to hundredths place.