JEE Main Chemistry question

[WB-JEE 2011] An electric current is passed through an aqueous solution of a mixture of alanine (isoelectric point 6.0), glutamic acid (3.2) and arginine (10.7) buffered at pH 6. What is the fate of the three acids?

(A)Glutamic acid migrates to the anode at pH 6. Arginine, present as a cation, migrates to the cathode. Alanine, in a dipolar ion, remains uniformly distributed in solution.Correct
(B)Glutamic acid migrates to the cathode and others remain uniformly distributed in solution.
(C)All three remain uniformly distributed in solution.
(D)All three move to the cathode.

Answer: (A)

Solution

At a buffered pH of 6, each amino acid's behaviour depends on its isoelectric point (pI) relative to this pH: alanine, whose pI (6.0) equals the buffer pH, remains at its isoelectric point as a neutral zwitterion and does not migrate. Glutamic acid, whose pI (3.2) is well below pH 6,

See the full step-by-step solution

Create a free account to read the complete working, and practise questions like this in a timed test.

Create a free account

Question ID VK-150683