To calculate the effect of adding the buffer solution, we can use the Henderson-Hasselbalch equation:pH = pKa + log [A-]/[HA] where pH is the solution's pH, pKa is the acid dissociation constant, [A-] is the concentration of the conjugate base acetate ion , and [HA] is the concentration of the weak acid acetic acid .Initially, we have a 0.1 M solution of acetic acid. When we add an equal volume of the buffer solution containing equal amounts of acetic acid and sodium acetate, the concentrations of acetic acid and acetate ion will be the same. Let's call this concentration x.Since the volumes of the acetic acid solution and the buffer solution are equal, the final volume will be twice the initial volume. Therefore, the final concentration of acetic acid will be:[HA] = 0.1 M / 2 = 0.05 MThe final concentration of acetate ion will be:[A-] = xNow we can use the Henderson-Hasselbalch equation to calculate the final pH:pH = 4.76 + log x/0.05 Since the buffer solution contains equal amounts of acetic acid and sodium acetate, the ratio [A-]/[HA] will be 1:pH = 4.76 + log 1 = 4.76So, the final pH of the solution after adding the buffer will be 4.76. This demonstrates the buffering capacity of the solution, as the pH remains close to the pKa value of acetic acid.