Alcohols, Phenols and Ethers

Edited By Team Careers360 | Updated on Aug 14, 2023 04:39 PM IST

Introduction:
Detergents, antiseptics, and scents are all made up of three basic compounds: Alcohols, Phenols, and Ethers.
You've learned that replacing one or more hydrogen atoms in a hydrocarbon with another atom or a group of atoms produces a totally new chemical with entirely different properties and applications. When a hydrogen atom in an aliphatic or aromatic hydrocarbon is replaced by a –OH group, alcohols and phenols are produced. These types of chemicals have a wide range of applications in both business and everyday life.

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Have you ever noted that ordinary spirit, which is used to polish wooden furniture, is mostly a hydroxyl group-containing molecule called ethanol? Compounds containing –OH groups are found in the sugar we eat, the cotton we wear, and the paper we write on. Consider life without paper: no notebooks, books, newspapers, cash notes, checks, or certificates, to name a few examples. Beautiful images and engaging tales would vanish from our lives, as would publications. It'd have been a very different planet.

A phenol has –OH group(s) directly attached to a carbon atom(s) of an aromatic system, whereas alcohol contains one or more hydroxyl (OH) group(s) directly attached to a carbon atom(s) of an aliphatic system (CH3OH) (C6H5OH).

Another class of compounds known as 'ethers' is formed when a hydrogen atom in a hydrocarbon is replaced by an alkoxy or aryloxy group (R–O/Ar–O). For example, CH3OCH3 (dimethyl ether).

List of topics according to NCERT and JEE Main/NEET syllabus:

Classification of Alcohols, Phenol, and Ethers
Structures of Functional Groups
Physical Properties
Preparation of Alcohols
Reactions of Alcohols
Preparation of Phenols
Ethers
Reaction of Ethers
Preparation of Epoxides
Reactions of Epoxides
Acidic Strength
Tests for Alcohols, Phenols, and Ethers

Important concepts and Laws:

Alcohols— Mono, Di, Tri or Polyhydric alcohols
Phenols— Mono, Di and trihydric phenols
Ethers
Common and IUPAC Names of Some Alcohols
Common and IUPAC Names of Some Ethers
Structures of Functional Groups
Preparation of Alcohols

From alkenes
From carbonyl compounds
From Grignard reagents

Preparation of Phenols

From haloarenes
From benzene sulphonic acid
From diazonium salts
From cumene

Physical Properties
Chemical Reactions
Reactions involving cleavage of O–H bond

The acidity of alcohols and phenols
Esterification

Reactions involving cleavage of carbon-oxygen (C–O) bond in alcohols

Reaction with hydrogen halides:
Reaction with phosphorus trihalides
Dehydration:
Oxidation:

Reactions of phenols

Electrophilic aromatic substitution
Kolbe’s reaction
Reimer-Tiemann reaction
The reaction of phenol with zinc dust
Oxidation

Some Commercially Important Alcohols
Preparation of Ethers

By dehydration of alcohols
By dehydration of alcohols
Physical Properties of ether

Chemical Reactions

Cleavage of C–O bond in ethers
Electrophilic substitution

Halogenation
Friedel-Crafts reaction
Nitration

Importance of Alcohols, Phenols and Ethers class 12:

Alcohol and ether are classes of organic compounds that find wide usage in industries as well as for domestic purposes. Alcohol is formed when a saturated carbon atom is bonded to a hydroxyl (-OH) group. Ether is formed when an oxygen atom is connected to two alkyl or aryl groups.

Although, in the JEE Examination, there are just one to two questions from Alcohols, Phenols and Ethers.

However, it is still very important.

The main concepts include the classification of alcohol and ether, preparation and important reactions. Alcohol and Ether is an important topic included in the JEE syllabus for organic chemistry. Questions based on their reactions and methods of preparation are asked almost every year in JEE.

NCERT Solutions Subject wise link:

NCERT Exemplar Solutions Subject wise link:

Frequently Asked Questions (FAQs)

1. Why do alcohols and phenols react differently?

Alcohols usually feature the hydroxyl group attached to aliphatic hydrocarbons. Phenols usually contain aromatic hydrocarbons. In comparison to phenol, alcohols are known to be less acidic. Phenols are relatively more acidic in nature and should, therefore, be diluted before usage.

2. What are the applications of Alcohols, Phenols, and Ethers?

The basic components used to make detergents, antiseptics, and perfumes are alcohols, phenols, and ethers, respectively.

3. What test is used to distinguish phenol from alcohol?

Test to distinguish between alcohol and phenols

1. Litmus test: Phenols turn blue litmus red and alcohols have no effect.
2. Ferric chloride test: Phenols give blue, green, and violet colour while alcohol gives no change in colour.
3. Bromine water test: Phenols gives white precipitates while alcohol gives no precipitates.

4. How do you tell the difference between alcohol, phenol, and ether?

A hydroxyl group is attached to a carbon atom of alcohols. —OH is attached to a benzene ring in phenols. (This class's "parent" molecule ule is also called phenol: PhOH or C6H5OH.) The ether functional group is formed when two carbon groups are connected to oxygen by single bonds.

5. Ortho nitrophenol has a lower boiling point than p-nitrophenol. Why?

Ortho-nitrophenol has a lower boiling point due to the formation of intramolecular H-bonding whereas p-nitrophenol forms intermolecular H-bonding.