Question

Although we normally think of acetic acid as an acid, it can also act as a weak base. Treated with a strong acid, it can became protonated. The conjugate add of acetic acid is shown below. Derive a resonance structure for this ion which, taken with the given structure, would show that the two -OH groups are equivalent, the two C-O bonds are equivalent, and the positive charge is shared equally by the two oxygens. The skeleton for the second resonance structure is provided below. Add the bond(s), charge(s), and unshared pairs of electrons. For both resonance structures below, draw the curved arrows to show the flow of electrons that transforms them into each other.

Answer 1

The resonance structure is as HaC 仫 OH

Answer 2

Concepts and reason

This problem is based on the concept of conjugate acid.

An acid on deprotonation gives an anion which is called its conjugate base and a base on protonation gives a cation which is called its conjugate acid. However, acetic acid can be protonated in order to give a conjugate acid.

Fundamentals

A resonating structure involves the conversion of pi-bonds to lone pairs and vice versa within the molecular structure. All the charges, lone pairs and bonds are shown in the resonating structure.

The structure of conjugate acid of acetic acid is as follows:

Resonating structure of the conjugate acid of acetic acid is given below.

The curved arrow representation of both the structures is as follows:

Ans:

The resonating structure of conjugate acid of acetic acid is given below:

The curved arrow representation of two resonating structures of conjugate acid of acetic acid is as follows: