A buffer solution is prepared by mixing 47.5 mL of 0.772 M carbonic acid with 58.8 mL of 0.0346 M sodium hydrogen carbonate.

1. Calculate the pH (to two decimal places) of this solution. Assume the 5% approximation is valid and that the volumes are additive.

2. Calculate the pH (to two decimal places) of the buffer solution after the addition of 7.77 g of sodium hydrogen carbonate (NaHOCOO) to the buffer solution above.

Assume 5% approximation is valid and that the volume of solution does not change.