According to the Henderson-Hasselbalch equation,when the concentrations of proton acceptor and proton donor are the same,then
A)the carboxylic acid is totally neutralized.
B)only salt forms are present.
C)pH = pKa.
D)pKa = log[proton acceptor]/[proton donor].

Question

Quizplus · Accepted Answer

The Henderson-Hasselbalch equation is pH = pKa + log([proton acceptor]/[proton donor]). When the concentrations of proton acceptor and proton donor are equal, then [proton acceptor]/[proton donor] = 1, and the log term becomes 0. Therefore, the equation simplifies to pH = pKa, which means that the pH of the solution is equal to the pKa of the acid. This is the point where the acid is half-neutralized and exists in its acidic and basic forms in equal proportions, and is called the acid's pKa. Therefore, choice C is the correct answer.

According to the Henderson-Hasselbalch Equation,when the Concentrations of Proton Acceptor