Rank the following in order of increasing pKa (from lowest to highest pKa).
A) 1

Question

Rank the following in order of increasing pKa (from lowest to highest pKa). 
A) 1 < 2 < 3 
B) 3 < 2 < 1 
C) 2 < 1 < 3 
D) 3 < 1 < 2 
E) 2 < 3 < 1

Quizplus · Accepted Answer

The pKa values of the functional groups are as follows: 
1. Carboxylic acid: ~5 
2. Phenol: ~10 
3. Amine: ~9.5 
Therefore, 2 has the lowest pKa, followed by 1, with 3 having the highest pKa. Thus, the correct order is 2 < 1 < 3. The only choice that reflects this order is C.

Rank the Following in Order of Increasing PKa (From Lowest