Benzoic acid, HC7H5O2, is a weak monoprotic acid. 10.81 g of sodium benzoate, NaC7H5O2, which is the conjugate base, is placed in a 0.500 L beaker and its pH is measured. It is found the pH of the solution is 8.69. Determine the value of the dissociation constant, Ka, for benzoic acid.
C7H5O2?(aq) + H2O(l) ? HC7H5O2(aq) + OH?(aq)