1. The problem statement, all variables and given/known data To prepare 1M phosphate buffer pH7.8. pKa=7.21. How much molar of Na2HPO4 and NaH2PO4 to be added I have no confidence in my answer... Can anyone pls have a check? 2. Relevant equations pH=pKa+lg (base/conjugate acid) 3. The attempt at a solution 7.8=7.21 +lg (a/b) 0.59=lg (a/b) a/b=3.89 a+b=1-----1 a=1-b -----2 (1-b)/b=3.89 b=0.2045 -Na2HPO4 a=0.7955 -NaH2PO4 Is my way of doing it correct? Did i forget to calculate other things that i must?