Engineering
Chemistry
pH Scale and Relative Strength of Acids
pH Calculation for Acids and Bases
Amino acids
Question

Within the list shown below, the correct pair of structures of alanine in pH range 2 – 4 and 9 – 11 is :
(I) H3 NCH(CH3)CO2H
(II) H2NCH(CH3)CO2
(III) H3 N+ CH(CH3)CO2
(IV) H2NCH(CH3)CO2H

(I), (II)

(I), (III)

(II), (III)

(III), (IV)

JEE Advance
College PredictorLive

Know your College Admission Chances Based on your Rank/Percentile, Category and Home State.

Get your JEE Main Personalised Report with Top Predicted Colleges in JoSA

Solution
Verified BY
Verified by Zigyan
As the isoelectric point of Alanine is 6.1.
At pH below pl it has NH3,
At pH above pl it has COO,
Option (A) is correct.