Difference Between Alcohol and Phenol

Alcohol is the most common organic compound and an abundant chemical produced in the industry. It can also be said that the alcoholic organic compounds are characterized by the presence of either one, two, or more hydroxyl groups (-OH) attached to the carbon atom of an alkyl group or hydrocarbon chain.


Alcohol is an organic compound where the molecules consist of one or more groups of hydroxyl. Besides, these are attached to a carbon atom. Alcohol is usually categorized as primary, secondary, and tertiary types. Such classification is generally done depending on which carbon of the alkyl is bonded to the hydroxyl group.


Characteristics of Alcohol

A famous alcohol characteristic is that they undergo oxidation readily.


In view of categories, primary alcohols oxidize to form aldehydes, and again aldehydes oxidize for producing carboxylic acids. Secondary alcohols only can oxidize once, resulting in ketones. Finally, the tertiary alcohols cannot be oxidized at all without breaking the carbon-carbon bonds.


Physical Properties of Alcohol

The presence of the hydroxyl group is the primary factor in determining the properties of Alcohol.


Few of the prominent physical properties include:

  • Boiling Point

Compared to other hydrocarbons, alcohols generally have higher boiling points. This can be associated with the presence of intermolecular hydrogen bonding between the hydroxyl groups of alcohol molecules.

  • Solubility of Alcohols

The hydroxyl group determines the solubility of alcohols. Hydroxyl group of Alcohol participates in the formation of intermolecular hydrogen bonding. So that hydrogen bonds between Alcohol and water make it soluble in water.

  • Acidity

Alcohols react with active metals like sodium and potassium and form the respective alkoxide. These reactions indicate their acidic nature, and this nature is due to the polarity of -OH bond. It is also said that the acidity of alcohol decreases when an electron-donating group is associated with the hydroxyl group.


What is Phenol?

Phenol is also a type of alcohol where the hydroxyl group is bound to an atomic ring. It is an exclusion to the rule that the hydroxyl group must be bounded to a saturated carbon. Phenol and its chemical derivatives are the primary ingredients for other compounds such as nylon, detergents, herbs, and pharmaceuticals.


Although phenols are more acidic compared to alcohols, we can say that phenols are considered as a subset of alcohol. And, it’s a fact that both alcohol and phenols contain a hydroxyl group. Phenols can also be named as carbolic acids. They also exhibit unique physical and chemical properties, mainly due to the presence of hydroxyl groups.


Physical Properties of Phenol

Let us discuss some of the physical properties of Phenol.

  • The boiling point of Phenols

Phenols also have higher boiling points compared to other hydrocarbons with equal molecular weight. The reason behind this is because of the intermolecular hydrogen bonding presence between hydroxyl groups of phenol molecules.

  • Solubility of Phenols

As the hydroxyl group determines the solubility of Phenol in water, and Phenol is completely responsible for the formation of intermolecular hydrogen bonding. As a result, hydrogen bonds form between water and phenol molecules making Phenol soluble in water.

  • Acidity

Phenols also react with the same active metals like potassium and sodium, resulting in the corresponding phenoxide. These reactions indicate phenols acidic in nature, the sp2 hybridized carbon of the benzene ring attached directly to the hydroxyl group acting as an electron-withdrawing group.


Now, we’ve learned many things about alcohol and phenol. Let’s look into the factors that differentiate these two chemical compounds.


Differences Between Alcohol and Phenol


Alcohol

Phenol

It is an organic compound where the molecule consists of one or more hydroxyl groups. 

Phenol is a compound consisting of a hydroxyl group with a direct bonding to an aromatic hydrocarbon group.

Alcohols are less acidic, compared to phenol.

In nature, phenols are acidic and should be diluted before going to use.

Regarding usage, alcohol is the main ingredient of alcoholic beverages and can also be used in ink, pharma, and more industries.

Phenols are mainly used in manufacturing medical products as antiseptic agents.

Mostly, alcohols are colorless and are in a liquid state.

Phenols can be found as colourless solids present in the form of crystals at room temperature. 

Since alcohols are mostly neutral, they do not show any reaction or impact while undergoing any test.

Since phenols are acidic in nature, they can change the litmus paper into the red.

Alcohol does not produce any colour.

Phenol gives a light yellow precipitate of its Bromo derivative.

Alcohols are aliphatic compounds.

Phenols are aromatic compounds.

The density of alcohol is about 789 kg/m3.

The density of Phenol is 1.07 g/m3.

Alcohols do not react to NaOH.

By reacting with NaOH, phenols form phenoxides.

FAQ (Frequently Asked Questions)

How will you Distinguish Alcohol and Phenol?

Phenol, aromatic alcohol, reacts easily with an aqueous solution of FeCl3 to give a violet color. On the other hand, no aliphatic alcohol (For example, ethyl alcohol, methyl alcohol, etc.) will react with a solution of FeCl3.


When handled with aqueous Br2 phenol, the white precipitate is 2,4,6-tribromophenol. However, aliphatic alcohols do not react with the solution of Br2.


Phenols have a hydroxyl group directly linked to the ring, whereas alcohols, as non-aromatic compounds, have a hydroxyl group linked to the main chain. The difference is one is cyclic, and the other is non-cyclic.

Why can you Pour Acid Directly into the Water, but Why can't Water in an Acid?

A significant amount of heat is emitted when strong acids are combined with water. Adding more acid obviously releases more heat. If you add water to the acid, you initially form a highly concentrated acid solution. Too much heat is emitted that the solution will boil very violently, splashing condensed acid out of the bottle!


If you apply acid to the water, the solvent that emerges is rather diluted, and the little amount of heat is produced which is not enough to vaporize and spatter the solution. So it's always advised Add Acid to water, but not vice versa.