A 1.50L buffer solution is 0.240M in HC₂H₃O₂ and 0.200M in NaC₂H₃O₂. Calculate the pH of the solution before and after the addition of 100.00mL of 0.12MHCl. Assume no volume change.
a) 2.74, 2.74
b) 2.86, 2.86
c) 2.74, 2.86
d) 2.86, 2.74