Calculate the CO3- concentration of a 5.45 x 10-4 M H2CO3 (carbonic acid) solution. Ka1 and Ka2 of carbonic acid are 4.3 x 10-7 and 4.8 x 10-11 respectively.
A buffer is prepared by mixing 525 mL of 0.50 M formic acid, HCHO2, and 475 mL of 0.50 M sodium formate, NaCHO2. Calculate the pH.