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Alcohols, Phenols and Ethers

NCERT Class 12 Chemistry Chapter 7

Alcohols, Phenols and Ethers for Class 12 Chemistry, JEE and NEET: preparation, reactions, acidity of phenols, dehydration and Williamson synthesis.

7 topics Updated 8 Nov 2026

For: Class 12, JEE and NEET, unless a topic says otherwise

In the syllabus: JEE Class 12 syllabus, NEET Class 12 syllabus

With your textbook

NCERT Chemistry Part II (Class 12), Chapter 7 “Alcohols, Phenols and Ethers”, reprint 2026-27.

Open the official NCERT chapter (PDF, 4.6 MB, ncert.nic.in)

Checked on 19 Oct 2026.

Learn in this order

  1. Classification of alcohols, phenols and ethers

    Mono- to polyhydric; 1°, 2°, 3°, allylic, benzylic, vinylic; symmetrical ethers.

    NCERT Section 7.1 11 min read 3 solved examples 6 practice questions

  2. Nomenclature of alcohols, phenols and ethers

    Common and IUPAC names, -ol and -diol, cresols, benzenediols, alkoxy names.

    NCERT Section 7.2 10 min read 3 solved examples 6 practice questions

  3. Structures of the alcohol, phenol and ether groups

    C–O–H and C–O–C angles, C–O bond lengths and why phenol’s C–O bond is shorter.

    NCERT Section 7.3 6 min read 2 solved examples 5 practice questions

  4. Alcohols and phenols: preparation and reactions

    Preparation, phenol from cumene, acidity and pKa, Lucas test, dehydration, oxidation and Kolbe’s reaction.

    NCERT Section 7.4 22 min read 5 solved examples 9 practice questions

  5. Experiment: tests for alcoholic and phenolic –OH groups

    Ceric ammonium nitrate, the Lucas and iodoform tests, neutral ferric chloride and the phthalein dye test.

    JEE and NEET only 14 min read 2 solved examples 7 practice questions

  6. Commercially important alcohols: methanol and ethanol

    Methanol from CO and hydrogen, ethanol by fermentation, their uses, methanol poisoning and denaturation.

    NCERT Section 7.5 10 min read 2 solved examples 7 practice questions

  7. Ethers: preparation, properties and reactions

    Dehydration of alcohols, Williamson synthesis, boiling points, cleavage by HI and electrophilic substitution in anisole.

    NCERT Section 7.6 13 min read 3 solved examples 7 practice questions

Key formulas in this chapter

Classification

  • 1° alcohol: –CHOH; 2°: >CH–OH; 3°: >C–OH
  • Allylic: CH=CH–CHOH; benzylic: CHCHOH
  • Vinylic: CH=CH–OH; phenol: CHOH
  • Symmetrical ether: CHOCH; unsymmetrical: CHOCH

Nomenclature

  • Alcohol: alkane − e + ol, as propan-2-ol
  • Diol, triol: ethane-1,2-diol; propane-1,2,3-triol
  • Cresols: 2-, 3-, 4-methylphenol
  • Benzenediols: 1,2 catechol; 1,3 resorcinol; 1,4 hydroquinone
  • Ether: alkoxyalkane, larger group as parent; CHOCH is methoxyethane

Structures of functional groups

  • C–O: phenol 136 pm < methoxymethane 141 pm < methanol 142 pm
  • Angle at O: methanol C–O–H 108.9°; phenol C–O–H 109°; methoxymethane C–O–C 111.7°
  • Tetrahedral angle: 109° 28′ (109.47°)

Alcohols and phenols

  • 2R–OH + 2Na → 2R–ONa + H
  • CHOH + NaOH → CHONa + HO
  • Acid strength: 1° > 2° ≫ 3° alcohol; ethanol < water < phenol
  • Cumene → cumene hydroperoxide → phenol + acetone
  • CHOH + 3Br → CHBrOH + 3HBr
  • Dehydration ease: 3° > 2° > 1°
  • Lucas reagent: conc. HCl + ZnCl
  • CHOH + Zn → CH + ZnO

Experiment: tests for –OH groups

  • (NH)[Ce(NO)] + 3ROH → [Ce(NO)(ROH)] + 2NHNO (red)
  • RCOH + HCl → RCCl + HO (ZnCl, at once)
  • CHCHOH + 4I + 6NaOH → CHI + HCOONa + 5NaI + 5HO
  • 6CHOH + FeCl → [Fe(CHO)] + 3HCl + 3H (violet)

Commercially important alcohols

  • Methanol: CO + 2H → CHOH (ZnO–CrO, 200–300 atm, 573–673 K)
  • Invertase: CHO + HO → CHO + CHO
  • Zymase: CHO → 2CHOH + 2CO
  • Boiling points: methanol 337 K, ethanol 351 K

Ethers

  • 2CHOH → CHOCH + HO (HSO, 413 K)
  • R–X + R′–ONa → R–O–R′ + NaX
  • R–O–R + HX → RX + R–OH
  • CHOCH + HI → CHOH + CHI
  • Reactivity: HI > HBr > HCl
  • b.p.: n-pentane 309.1 K, ethoxyethane 307.6 K, butan-1-ol 390 K

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