To analyze the effect of adding a buffer to a solution containing acetic acid and sodium acetate, we need to consider the acid-base equilibrium between acetic acid CH3COOH and acetate ions CH3COO- . The equilibrium reaction can be represented as:CH3COOH aq + H2O l CH3COO- aq + H3O+ aq The equilibrium constant for this reaction is given by the acid dissociation constant Ka of acetic acid:Ka = [CH3COO-][H3O+] / [CH3COOH]First, let's assume we have a solution containing 0.1 M acetic acid and 0.1 M sodium acetate. Sodium acetate dissociates completely in water to give acetate ions:NaCH3COO aq Na+ aq + CH3COO- aq Now, let's calculate the pH of the solution using the Henderson-Hasselbalch equation:pH = pKa + log [CH3COO-] / [CH3COOH] The pKa of acetic acid is 4.75. Since the concentrations of acetic acid and acetate ions are equal 0.1 M , the pH of the solution can be calculated as:pH = 4.75 + log 0.1 / 0.1 = 4.75Now, let's consider adding a buffer to the solution. A buffer is a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid that resists changes in pH upon the addition of small amounts of acid or base. In this case, the acetic acid and acetate ions already form a buffer system. Adding more of the same buffer components will not change the equilibrium position of the acid-base reaction, but it will increase the buffer capacity, meaning the solution will be able to resist pH changes more effectively.Let's assume we add 0.1 M of acetic acid and 0.1 M of sodium acetate to the solution, resulting in a new concentration of 0.2 M for both acetic acid and acetate ions. The pH of the solution can be calculated again using the Henderson-Hasselbalch equation:pH = 4.75 + log [CH3COO-] / [CH3COOH] = 4.75 + log 0.2 / 0.2 = 4.75As we can see, the pH of the solution remains the same, indicating that the equilibrium position of the acid-base reaction between acetic acid and acetate ions has not changed. However, the buffer capacity has increased, allowing the solution to better resist changes in pH upon the addition of small amounts of acid or base.