For 510.0 mL of a buffer solution that is 0.125 M in HC2 H3 O2 and 6.50x10-2 M in NaC, H3 O2, calculate the initial pH and the final pH after adding 1.5x10-2 mol of HCl. (Ka (HC2H;O2) = 1.8 x 10-5.) Express your answers using two decimal places separated by a comma. ? pHinitial pHfinal =