Question

How much benzoic acid, Ka = 6.3 X 10-6, will remain undissociated in the aqueous phase of a 50%oil-water emulsion if the initial concentration of benzoic acid in the aqueous phase is 0.5%? The aqueous phase is buffered at pH 5 and the o/w partition coefficient = 6.33. Assume that benzoic acid remains as a * .monomer in the oil phase

Answer 1

Without additional volume or mass data, the exact mass of undissociated benzoic acid cannot be calculated, but the partition coefficient and pH impact the dissociation in the aqueous phase.

Step-by-step explanation:

To determine how much benzoic acid remains undissociated in the aqueous phase of a 50% oil-water emulsion, we need to understand the concept of partition coefficients and acid dissociation constants (Ka). The given Ka for benzoic acid is 6.3 x 10-6, and it is in a buffer solution at pH 5. Using the Henderson-Hasselbalch equation, we can find the ratio of dissociated to undissociated acid. Unfortunately, without additional information on the total volume or mass of the solution, we cannot determine the exact mass of undissociated benzoic acid directly. However, we can state that the undissociated acid will have a higher concentration in the water phase than the oil phase due to the partition coefficient, and that the percentage of dissociated acid will be influenced by the pH of the solution relative to the pKa of benzoic acid.