Question

Assume you have 1 L of each of the buffer solution described inparts 1 and 2 (part 1: 0.40 M in both HC2H3O2 and NaC2H3O2. Part 2:0.10 M in HC2H3O2 and 0.40 M in NaC2H3O2). To which buffer solutioncould you add the larger colume of 0.10 M NaOH solution withoutcausing a pH change of more than one or two pH units?

Please explain how you came up with answer I really want tounderstand how to calculate this

Thanks!