Preparing a Buffer Solution
Calculate the mass (g) of pure Na3AsO4 (s) and volume (mL) of 1.50 M HCl that are required to make 100.0 mL of a buffer solution at a pH of 6.80 and an H2AsO4-(aq) concentration of 0.100 M. The MW of Na3AsO4 is 207.862 g/mol and for H3AsO4, pKa1 = 2.24, pKa2 = 6.96, and pKa3 = 11.50.