In what form do aliphatic amines exist at physiological pH (pH= 7.4)?
A) largely as neutral molecules
B) largely as their conjugate acids
C) as a mixture of neutral molecules and their conjugate acid, but with a slight predominance of the conjugate acid
D) as a 50/50 mixture of neutral molecules and their conjugate acids

Question

Quizplus · Accepted Answer

At physiological pH (7.4), aliphatic amines are largely protonated, existing as their conjugate acids due to the pKa of amines being around 9-11, which is higher than 7.4.

In What Form Do Aliphatic Amines Exist at Physiological PH