Q61E - Organic Chemistry (Mcmurry)

Question

Phenol,${\mathbf{C}}_{\mathbf{6}}{\mathbf{H}}_{\mathbf{5}}\mathbf{OH}$, is a stronger acid than methanol, ${\mathbf{CH}}_3\mathbf{OH}$, even though both contain an OH bond. Draw the structures of the anions resulting from loss of ${\mathbf{H}}^{\mathbf{+}}$ from phenol and methanol, and use resonance structures to explain the difference in acidity.

Step-by-Step Solution

Answer

                                      Resonance forms of phenol

Step 1: Definition of Resonance structure

The structures which are formed by the electronic displacement of 𝛑 bond present in the molecule. These are known as resonance structures

Step 2: Draw the anions of the phenol and methanol

                                       Resonance structures of phenol

Anion of compound can be formed by removing the hydrogen which is attached to electronegative atom

Step 3: Explanation of the stronger acidity in phenol

Due to the presence resonance structure in ${\text{C}}_6{\text{H}}_5{\text{O}}^{\mathbf{-}}$(by removing ${\mathrm{H}}^{+}$from ${\text{C}}_6{\text{H}}_5\text{OH}$   ) and hence it is more stable than methanol.

As no such factor exist in methanol