Introduction to Alcohols, Phenols, and Ethers

Alcohols, phenols, and ethers are important topics in NEET Organic Chemistry. These are oxygen-containing functional groups, and understanding their structure, properties, and reactions is crucial for NEET.

• Alcohols (R-OH): Hydroxyl group attached to sp³-hybridized carbon.

• Phenols (Ar-OH): Hydroxyl group attached directly to an aromatic ring.

• Ethers (R-O-R’): Oxygen atom bonded to two alkyl or aryl groups.

These compounds are frequently tested in NEET MCQs, matching, and reasoning questions.

Direct Links to Download 2025-26 Formula Chemistry (PDF)

► Click “Download Now” next to your subject to access the free PDF.

♦ Some Basic Concepts of Chemistry ⇒ Download Now

♦ Structure of Atom ⇒ Download Now

♦ Classification of Elements and Periodicity in Properties ⇒ Download Now

♦ Chemical Bonding and Molecular Structure ⇒ Download Now

♦ Thermodynamics ⇒ Download Now

♦ Equilibrium ⇒ Download Now

♦ Redox Reactions ⇒ Download Now

♦ s-Block Elements (Alkali and Alkaline Earth Metals) ⇒ Download Now

♦ Some p-Block Elements ⇒ Download Now

♦ p-Block Elements ⇒ Download Now

♦ Some Basic Principles and Techniques ⇒ Download Now

♦ Hydrocarbons ⇒ Download Now

♦ Solutions ⇒ Download Now

♦ Electrochemistry ⇒ Download Now

♦ Chemical Kinetics ⇒ Download Now

♦ Surface Chemistry ⇒ Download Now

♦ General Principles and Processes of Isolation of Elements ⇒ Download Now

♦ d and f Block Elements ⇒ Download Now

♦ Coordination Compounds ⇒ Download Now

♦ Haloalkanes and Haloarenes ⇒ Download Now

♦ Alcohols, Phenols and Ethers ⇒ Download Now

♦ Aldehydes, Ketones and Carboxylic Acid ⇒ Download Now

♦ Organic Compounds Containing Nitrogen ⇒ Download Now

♦ Biomolecules ⇒ Download Now

♦ Polymers ⇒ Download Now

♦ Chemistry in Everyday Life ⇒ Download Now

Nomenclature

Alcohols:

• IUPAC: Replace “-e” of alkane with “-ol” and indicate position of -OH.

  • Example: CH3CH2OH → Ethanol

Phenols:

• Named by adding “-phenol” to the parent aromatic ring.

  • Example: C6H5OH → Phenol

Ethers:

• Named as alkoxyalkanes or using common names based on alkyl groups.

  • Example: CH3OCH3 → Dimethyl ether

Correct nomenclature is frequently tested in NEET for structure identification.

Physical Properties

• Boiling Points: Alcohols > Phenols > Ethers due to hydrogen bonding.

• Solubility: Alcohols and phenols are water-soluble due to -OH; ethers are less soluble.

• Density: Generally higher than corresponding hydrocarbons.

• Odor and state: Alcohols and ethers are often liquids; phenols are solid or crystalline.

Physical properties are connected with hydrogen bonding, polarity, and molecular weight, which are important for NEET reasoning questions.

Acidity and Basicity

• Alcohols: Weakly acidic (ROH ⇌ RO⁻ + H⁺).

• Phenols: More acidic than alcohols due to resonance stabilization of phenoxide ion.

• Ethers: Neutral, generally do not act as acids or bases.

NEET often tests relative acidity using structural reasoning.

Reactions of Alcohols

1. Oxidation

   • Primary → Aldehyde → Carboxylic acid

   • Secondary → Ketone

   • Tertiary → Resistant to oxidation

2. Dehydration

   • Forms alkenes using acid catalyst (e.g., H2SO4).

3. Substitution

   • Reaction with HX to form alkyl halides.

4. Esterification

   • Reacts with carboxylic acids in presence of acid to form esters.

Mechanisms and reactivity trends are often tested in NEET.

Reactions of Phenols

1. Electrophilic Aromatic Substitution (EAS)

   • Hydroxyl group is activating and ortho/para-directing.

   • Reactions include halogenation, nitration, sulfonation.

2. Acid-Base Reactions

   • Phenol reacts with NaOH to form phenoxide ion.

3. Oxidation

   • Phenols can undergo oxidation to quinones.

4. Esterification

   • Reacts with acid chlorides or anhydrides to form esters.

Phenols’ enhanced reactivity compared to alcohols is a high-yield NEET concept.

Reactions of Ethers

1. Cleavage by HX

   • Forms alkyl halides.

2. Combustion

   • Burns to form CO2 and H2O.

3. Stability

   • Ethers are relatively inert, making them good solvents in organic reactions.

NEET questions often focus on reactivity differences between alcohols, phenols, and ethers.

Mechanisms to Focus On

• Nucleophilic substitution in alcohols (SN1 & SN2).

• Electrophilic substitution in phenols (orientation and reactivity).

• Acid-catalyzed dehydration for alcohols.

Understanding mechanisms helps in solving reasoning-based NEET questions.

Comparative Study

Comparison tables are useful for quick NEET revision.

Applications

1. Alcohols: Solvents, antiseptics, fuels, intermediates in chemical synthesis.

2. Phenols: Disinfectants, antioxidants, precursors for resins and drugs.

3. Ethers: Organic solvents, anesthetics (e.g., diethyl ether), intermediates in chemical industry.

Relating reactions and properties to applications strengthens conceptual understanding for NEET.

Tips for NEET Students

1. Focus on physical properties and acidity trends.

2. Revise mechanisms of substitution, elimination, and EAS reactions.

3. Use comparison tables to memorize differences among alcohols, phenols, and ethers.

4. Practice reasoning-based MCQs on reactivity and orientation.

5. Link applications with reactions and properties for better retention.

Conclusion

Alcohols, Phenols, and Ethers are high-yield, conceptual topics in NEET Organic Chemistry. Mastering structure, properties, acidity, reactions, and applications enables students to confidently answer a variety of NEET questions.

At StudentBro.in, we provide concise, exam-focused notes for NEET 2026 aspirants, enabling them to revise efficiently, strengthen conceptual clarity, and score higher in exams.