posted by matt on .
what is the pH of the buffer when 4ml of 1M HCl is added to a 100ml buffer solution made using 5ml 1M Na2HPO4 and 5ml 1M NaH2PO4? The pKa for H+ + HPO4- ==> H2PO4 is 6.82.
What would happen to the pH if the 100ml buffer had been made up at the starting pH (6.82) using Tris (total Tris concentration is 100mM) instead? Tris has a pKa of 8.08.