you have a 0.200L of solution containing 250mM phosphate buffer, pH 6.8.

Question

An equivalent amount of HCl/NaOH with respect to the total amount of phosphate in the buffer --> mmol of NaH2PO3 + mmol of NaH2PO4 = 50 mmoles.

What would the pH of the above buffer solution be after you add the following with respect to the total amount of phosphate in the buffer:

1) 1/8 equivalent amount of NaOH
2) 1/8 equivalent amount of HCl

Answer 1

1) 5.89
2) 11.47

Answer 2

How did you solve it? I wasn't really looking for an answer but the process because I don't really get it.