# How does phenol differ from benzene?

Jul 7, 2018

$\textcolor{red}{\text{COMPARISON GIVEN BELOW}}$

#### Explanation:

Both Benzene and Phenol are aromatic compounds.

Benzene:-

1. molecular formula of ${C}_{6} {H}_{6}$
2. Neutral in nature and mostly acts as a solvent
3. Possess a sweet odor.
4. Colorless liquid
5. Less polar in nature than phenol
6. Less soluble in water than phenol
7. Faster evaporation.

Phenol:-

1. molecular formula ${C}_{6} {H}_{6} O H$
2. Acidic in nature
3. Possess a strong odor.
4. Phenol in solid form is white crystalline color.
5. More polar in nature than benzene.
6. Easily soluble in water
7. Slower evaporation.

Jul 7, 2018

Simply by the presence of the hydroxyl functional group...

#### Explanation:

And of course the hydroxyl group confers vastly different chemical and physical properties.

We got benzene, ${C}_{6} {H}_{6}$, and phenol, ${C}_{6} {H}_{5} O H$. Benzene is a volatile liquid under normal conditions, with a normal boiling point of $80.1$ ""^@C. Phenol is a low melting solid, with a normal boiling point of $181.7$ ""^@C.

This difference in volatilities relates to the degree of $\text{INTERMOLECULAR FORCE}$, i.e. the force between molelcules...NOT the force between atoms within the molecule, the $\text{INTRAMOLECULAR FORCE}$...and please note the distinction.

And why should phenol have a greater intermolecular force? Well, due to the presence of the hydroxyl group that offers the possibility of $\text{intermolecular hydrogen bonding}$. Thus the boiling point of phenol is ELEVATED, as are the boiling points of water, and methyl alcohol, and ethyl alcohol, the which are all elevated under relevant comparison.

And chemically, the hydroxyl substitution makes phenol a much more reactive substrate in the context of aromatic electrophilic substitution. To achieve this for the benzene ring, often some Lewis-acidic catalyst has to be added, before the ring reacts with an electrophile. For phenol, OFTEN, this catalyst may be omitted, and substitution occurs facilely.