A given volume of buffer solution contains 6.85 x 10-3 mol of the weak acid HY and 2.98 x 10-3 mol of the salt NaY. The pH of the buffer solution is 3.78.
A) Calculate the value of pKa for the acid HY at this temperature
B) State and explain the effect on the pH of the buffer solution when a small amount HCl is added