A distribution curve shows how fractions of non-ionized acid and its conjugate base vary as a function of Ph. The curves of the plot of [CH3COOH] vs. [CH3COO-] vs. PHwill intersect at a Ph of What?

To find the pH at which the curves of the plot of [CH3COOH] (concentration of non-ionized acid) and [CH3COO-] (concentration of conjugate base) intersect, we need to consider the Henderson-Hasselbalch equation. This equation relates the pH of a solution to the concentration of the acid and its conjugate base:

pH = pKa + log([A-]/[HA])

Where pH is the given pH value, pKa is the acid dissociation constant (a measure of the acidity of the acid), [A-] is the concentration of the conjugate base, and [HA] is the concentration of the non-ionized acid.

The point of intersection occurs when the concentration of the conjugate base is equal to the concentration of the acid. In other words, when [A-] = [HA].

Therefore, using the Henderson-Hasselbalch equation:

pH = pKa + log(1)

Since log(1) = 0, we can simplify the equation:

pH = pKa

Thus, the pH at which the curves of the plot of [CH3COOH] and [CH3COO-] intersect is equal to the pKa of the acid.