The pKa value of acetic acid CH3COOH is approximately 4.76. This value indicates the acidity of acetic acid, with lower pKa values corresponding to stronger acids.When acetic acid is mixed with a strong base like sodium hydroxide NaOH , an acid-base reaction occurs. The reaction can be represented by the following equation:CH3COOH + NaOH CH3COONa + H2OIn this reaction, acetic acid donates a proton H+ to the hydroxide ion OH- from sodium hydroxide, forming water H2O and the acetate ion CH3COO- . The sodium ion Na+ from sodium hydroxide remains as a spectator ion and does not participate in the reaction.To determine the pH of the resulting solution, we need to know the initial concentrations of acetic acid and sodium hydroxide, as well as the volume of the solution. For simplicity, let's assume we have a 1.0 L solution containing 1.0 mol of acetic acid and 1.0 mol of sodium hydroxide.Using the stoichiometry of the reaction, we can determine that 1.0 mol of acetic acid will react with 1.0 mol of sodium hydroxide, producing 1.0 mol of acetate ion and 1.0 mol of water. Since the reaction goes to completion due to the strong base , there will be no remaining acetic acid or sodium hydroxide in the solution.Now, we can use the Henderson-Hasselbalch equation to determine the pH of the solution:pH = pKa + log [A-]/[HA] In this case, [A-] is the concentration of the acetate ion CH3COO- and [HA] is the concentration of acetic acid CH3COOH . Since all the acetic acid has reacted, [HA] = 0, and [A-] = 1.0 mol/L. Plugging these values into the equation, we get:pH = 4.76 + log 1.0/0 Since the log of infinity is undefined, this equation does not give us a valid pH value. However, this result indicates that the pH of the solution will be significantly higher than the pKa of acetic acid, as the strong base has neutralized the weak acid completely. In practice, the pH of the solution would be determined by the concentration of the acetate ion and any remaining hydroxide ions, if present.