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Chemistry · Textbook solutions

Alcohols, Phenols and Ethers

Every solved example, exercise, and miscellaneous question — in the order the textbook teaches them. Plus every board question asked from this chapter. · 39 questions

11. Alcohols, Phenols and Ethers — worked examples

9 q

Solved Examples

Worked · 9
  1. Solved Ex.11.1
    Draw structures of following compounds. i. 2,5-Diethylphenol ii. Prop-2-en-1-ol iii. 2-methoxypropane iv. Phenylmethanol
  2. Solved Ex.11.2
    Predict the products for the following reaction. CH3−CH=CH−CH2−CHO\mathrm{CH_3-CH{=}CH-CH_2-CHO} (A) i. with H2/Ni\mathrm{H_2/Ni} ii. with (i) LiAlH4\mathrm{LiAlH_4} (ii) H3O⊕\mathrm{H_3O^{\oplus}}
  3. Solved Ex.11.3
    The boiling points of n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol and tert-butyl alcohol are 118∘C118^\circ\mathrm{C}, 108∘C108^\circ\mathrm{C}, 99.5∘C99.5^\circ\mathrm{C} and 83∘C83^\circ\mathrm{C} respectively. Explain.
  4. Solved Ex.11.4
    The solubility of o-nitrophenol and p-nitrophenol is 0.2 g0.2\ \mathrm{g} and 1.7 g/100 g1.7\ \mathrm{g}/100\ \mathrm{g} of H2O\mathrm{H_2O} respectively. Explain the difference.
  5. Solved Ex.11.5
    Arrange the following compounds in decreasing order of acid strength and justify. i. CH3−CH2−OH\mathrm{CH_3-CH_2-OH} ii. (CH3)3C−OH\mathrm{(CH_3)_3C-OH} iii. C6H5−OH\mathrm{C_6H_5-OH} iv. p-NO2−C6H4−OH\mathrm{p\text{-}NO_2-C_6H_4-OH}
  6. Solved Ex.11.6
    Write the reaction showing major and minor products formed on heating butan-2-ol with concentrated sulfuric acid.
  7. Solved Ex.11.7
    Write and explain reactions to convert propan-1-ol into propan-2-ol.
  8. Solved Ex.11.8
    An organic compound gives hydrogen on reaction with sodium metal. It forms an aldehyde having molecular formula C2H4O\mathrm{C_2H_4O} on oxidation with pyridinium chlorochromate. Name the compounds and give equations of these reactions.
  9. Solved Ex.11.9
    Ethyl isopropyl ether does not form on reaction of sodium ethoxide and isopropyl chloride. C2H5−ONa+Cl−CH(CH3)−CH3↛C2H5−O−CH(CH3)−CH3\mathrm{C_2H_5-ONa} + \mathrm{Cl-CH(CH_3)-CH_3} \nrightarrow \mathrm{C_2H_5-O-CH(CH_3)-CH_3} i. What would be the main product of this reaction ? ii. Write another reaction suitable for the preparation of ethyl isopropyl ether.

Exercise

30 q

1. Choose the correct option.

Practice · 10
  1. Choose the correct option.
    Ex Q.1 (i)
    Which of the following represents the increasing order of boiling points of (1), (2) and (3)? (1) CH3−CH2−CH2−CH2−OH\mathrm{CH_3-CH_2-CH_2-CH_2-OH} (2) (CH3)2CH−O−CH3\mathrm{(CH_3)_2CH-O-CH_3} (3) (CH3)3COH\mathrm{(CH_3)_3COH}
    1. A.
      (1)<(2)<(3)(1) < (2) < (3)
    2. B.
      (2)<(1)<(3)(2) < (1) < (3)
    3. C.
      (3)<(2)<(1)(3) < (2) < (1)
    4. D.
      (2)<(3)<(1)(2) < (3) < (1)
  2. Ex Q.1 (ii)
    Which is the best reagent for carrying out following conversion ? 1-methylcyclohex-1-ene ⟶\longrightarrow 2-methylcyclohexan-1-ol
    1. A.
      LiAlH4\mathrm{LiAlH_4}
    2. B.
      Conc. H2SO4\mathrm{H_2SO_4}, H2O\mathrm{H_2O}
    3. C.
      H2/Pd\mathrm{H_2/Pd}
    4. D.
      B2H6\mathrm{B_2H_6}, H2O2\mathrm{H_2O_2}-NaOH\mathrm{NaOH}
  3. Ex Q.1 (iii)
    Which of the following reaction will give ionic organic product on reaction ?
    1. A.
      CH3−CH2−OH+Na⟶\mathrm{CH_3-CH_2-OH} + \mathrm{Na} \longrightarrow
    2. B.
      CH3−CH2−OH+SOCl2⟶\mathrm{CH_3-CH_2-OH} + \mathrm{SOCl_2} \longrightarrow
    3. C.
      CH3−CH2−OH+PCl5⟶\mathrm{CH_3-CH_2-OH} + \mathrm{PCl_5} \longrightarrow
    4. D.
      CH3−CH2−OH+H2SO4⟶\mathrm{CH_3-CH_2-OH} + \mathrm{H_2SO_4} \longrightarrow
  4. Ex Q.1 (iv)
    Which is the most resistant alcohol towards oxidation reaction among the follwoing ?
    1. A.
      CH3−CH2−OH\mathrm{CH_3-CH_2-OH}
    2. B.
      (CH3)2CH−OH\mathrm{(CH_3)_2CH-OH}
    3. C.
      (CH3)3C−OH\mathrm{(CH_3)_3C-OH}
    4. D.
      C2H5−CH(CH3)−OH\mathrm{C_2H_5-CH(CH_3)-OH}
  5. Ex Q.1 (v)
    Resorcinol on distillation with zinc dust gives
    1. A.
      Cyclohexane
    2. B.
      Benzene
    3. C.
      Toluene
    4. D.
      Benzene-1, 3-diol
  6. Ex Q.1 (vi)
    Anisole on heating with concerntrated HI gives
    1. A.
      Iodobenzene
    2. B.
      Phenol + Methanol
    3. C.
      Phenol + Iodomethane
    4. D.
      Iodobenzene + methanol
  7. Ex Q.1 (vii)
    Which of the following is the least acidic compound ?
    1. A.
      C6H5−OH\mathrm{C_6H_5-OH}
    2. B.
      4-CH3−C6H4−OH\mathrm{4\text{-}CH_3-C_6H_4-OH}
    3. C.
      3-NO2−C6H4−OH\mathrm{3\text{-}NO_2-C_6H_4-OH}
    4. D.
      4-NO2−C6H4−OH\mathrm{4\text{-}NO_2-C_6H_4-OH}
  8. Ex Q.1 (viii)
    The compound incapable of hydrogen bonding with water is ......
    1. A.
      CH3−CH2−O−CH3\mathrm{CH_3-CH_2-O-CH_3}
    2. B.
      CH3−CH2−CH2−CH3\mathrm{CH_3-CH_2-CH_2-CH_3}
    3. C.
      C6H5−OH\mathrm{C_6H_5-OH}
    4. D.
      CH3−CH2−CH2−OH\mathrm{CH_3-CH_2-CH_2-OH}
  9. Ex Q.1 (ix)
    Ethers are kept in air tight brown bottles because
    1. A.
      Ethers absorb moisture
    2. B.
      Ethers evaporate readily
    3. C.
      Ethers oxidise to explosive peroxide
    4. D.
      Ethers are inert
  10. Ex Q.1 (x)
    Ethers reacts with cold and concentrated H2SO4\mathrm{H_2SO_4} to form
    1. A.
      oxonium salt
    2. B.
      alkene
    3. C.
      alkoxides
    4. D.
      alcohols

2. Answer in one sentence/ word.

Practice · 4
  1. Answer in one sentence/ word.
    Ex Q.2 (i)
    Hydroboration-oxidation of propene gives.....
  2. Ex Q.2 (ii)
    Write the IUPAC name of alcohol having molecular formula C4H10O\mathrm{C_4H_{10}O} which is resistant towards oxidation.
  3. Ex Q.2 (iii)
    Write structure of optically active alcohol having molecular formula C4H10O\mathrm{C_4H_{10}O}
  4. Ex Q.2 (iv)
    Write name of the electrophile used in Kolbe's Reaction.

3. Answer in brief.

Practice · 6
  1. Answer in brief.
    Ex Q.3 (i)
    Why phenol is more acidic than ethyl alcohol ?
  2. Ex Q.3 (ii)
    Why p-nitrophenol is a stronger acid than phenol ?
  3. Ex Q.3 (iii)
    Write two points of difference between properties of phenol and ethyl alcohol.
  4. Ex Q.3 (iv)
    Give the reagents and conditions necessary to prepare phenol from a. Chlorobenzene b. Benzene sulfonic acid.
  5. Ex Q.3 (v)
    Give the equations of the reactions for the preparation of phenol from isopropyl benzene.
  6. Ex Q.3 (vi)
    Give a simple chemical test to distinguish between ethanol and ethyl bromide.

4. Structure deduction

Practice · 1
  1. Ex Q.4
    An ether (A), C5H12O\mathrm{C_5H_{12}O}, when heated with excess of hot HI produce two alkyl halides which on hydrolysis form compound (B) and (C), oxidation of (B) gave and acid (D), whereas oxidation of (C) gave a ketone (E). Deduce the structural formula of (A), (B), (C), (D) and (E).

5. Write structural formulae for

Practice · 5
  1. Write structural formulae for
    Ex Q.5 (a)
    3-Methoxyhexane
  2. Ex Q.5 (b)
    Methyl vinyl ether
  3. Ex Q.5 (c)
    1-Ethylcyclohexanol
  4. Ex Q.5 (d)
    Pentane-1,4-diol
  5. Ex Q.5 (e)
    Cyclohex-2-en-1-ol

6. Write IUPAC names of the following

Practice · 4
  1. Write IUPAC names of the following
    Ex Q.6 (i)
    i. Write the IUPAC name of the compound shown in the figure.
  2. Ex Q.6 (ii)
    ii. CH3−CH(OH)−CH(CH3)−CH2−OH\mathrm{CH_3-CH(OH)-CH(CH_3)-CH_2-OH}
  3. Ex Q.6 (iii)
    iii. Write the IUPAC name of the compound shown in the figure.
  4. Ex Q.6 (iv)
    iv. Write the IUPAC name of the compound shown in the figure.