Question

A student gives the following mechanism for a carboxylic acid deprotonation. All three arrows are incorrectly drawn. Correct the student\'s incorrect answer to give a valid mechanism.

Question 22 of 23 Map o sapling learning A student gives the following mechanism for a carboxylic acid deprotonation. All three arrows are incorrectly drawn. Correct the student's incorrect answer to give a valid mechanism. 0* NH3 +NH4 - O Previous ⓧ Give Up & View Solution O Check Answer Next Exit Hint

Answer 1

Concepts and reason

The concept used to solve this problem is the movement of electron towards higher electronegative atom.

Fundamentals

The acids when reacts with the base it loses the proton and convert itself into conjugate base. The carboxylic acid when losses its proton on the attack of ammonia as base, the carboxylate ion is formed as the conjugate base.

The lone pair of the base ${\rm{N}}{{\rm{H}}_3}$ abstracts proton from the acetic acid. Thus, forming the acetate ion ${\rm{C}}{{\rm{H}}_3}{\rm{CO}}{{\rm{O}}^ - }$ as conjugate base stabilized by the resonance and the ${\rm{NH}}_4^ +$ ammonium ion.

The conjugate base carboxylate ion is stabilized by the resonance which enhance the rate of acid base reaction and proceed the overall reaction in the forward direction.

The abstraction of ${{\rm{H}}^ + }$ and the stabilization of carboxylate ion occurs simultaneously in a concerted manner.

Ans:

The valid mechanism for the carboxylic acid deprotonation via ammonia base is as follows: