Alcohols Phenols and Ethers

33 solved questions from Class 12 Chemistry, each with the full working. Tap any question to see the step-by-step solution.

• 1 What is the primary chemical reaction or bonding mechanism highlighted in 'Alcohols Phenols and Ethers' (Class 12)? medium MCQ Reaction Mechanism & Bonding
• 2 What factor affects the rate or equilibrium constant of reactions in 'Alcohols Phenols and Ethers'? medium MCQ Chemical Kinetics & Factors
• 3 Which functional group or IUPAC nomenclature rule applies to compounds in 'Alcohols Phenols and Ethers'? medium MCQ IUPAC Nomenclature & Structure
• 4 What is the major product obtained in the characteristic reaction of 'Alcohols Phenols and Ethers'? medium MCQ Reaction Products & Selectivity
• 5 When diethyl ether (CH3CH2-O-CH2CH3) is treated with 2 equivalents of HBr at room temperature, what is the major product? medium 2 marks Cleavage of ethers by HBr
• 6 For the reaction phenol + NaOH ⇌ phenoxide- + H2O, calculate the equilibrium constant K using the given Ka of phenol = 1.3×10⁻¹⁰. hard 3 marks Acid–base equilibrium constants
• 7 Give the IUPAC name of the compound: CH3-CH(CH3)-CH(OH)-CH3. easy 1 mark IUPAC nomenclature of alcohols
• 8 When 2-methyl-2-butanol (CH3-C(CH3)2-CH2OH) is heated with conc. H2SO4, what is the major product? medium 2 marks Dehydration of alcohols
• 9 When 1‑phenylethanol is oxidised with pyridinium chlorochromate (PCC), what is the major product? Provide its common name and IUPAC name. medium 2 marks Oxidation of secondary alcohols
• 10 In the Williamson ether synthesis, which of the following statements is true? medium MCQ 2 marks Williamson ether synthesis
• 11 Calculate the pH of a 0.010 M solution of phenol (C_6H_5OH) at 25°C given K_a = 1.3×10^-10. medium 2 marks Acidity of phenols
• 12 When ethanol (CH_3CH_2OH) is oxidized with alkaline potassium permanganate (KMnO_4), what is the major product? State its common name and its IUPAC name. easy 1 mark Oxidation of primary alcohols
• 13 When 3‑methyl‑1‑butanol (CH_3CH_2CH(CH_3)CH_2OH) is heated with concentrated H_2SO_4 at 170°C, predict the major alkene product. Explain the mechanism and apply Zaitsev’s rule. hard 3 marks Acid‑catalyzed dehydration & Zaitsev’s rule
• 14 4. A buffer solution is prepared by dissolving 0.025 M phenol (C_6H_5OH) and 0.015 M sodium phenoxide (C_6H_5ONa) in water at 25°C. Given K_a(phenol) = 1.3×10^-10, calculate the pH of the solution. hard 5 marks Buffer pH calculation (Henderson–Hasselbalch)
• 15 3. When 2‑methyl‑2‑butanol ((CH_3)_3CCH_2OH) is heated with concentrated H_2SO_4 at 170°C, predict the major alkene product and explain the mechanism using Zaitsev’s rule. medium 3 marks Acid‑catalysed dehydration of alcohols
• 16 2. In Williamson ether synthesis, which of the following pairs of reactants will directly give ethyl phenyl ether (C_2H_5OC_6H_5)? medium MCQ 2 marks Williamson ether synthesis reagents
• 17 1. 1-Butanol (CH_3CH_2CH_2CH_2OH) and 2-methyl‑1‑propanol ((CH_3)_2CHCH_2OH) are structural isomers. State the type of isomerism they exhibit. easy 1 mark Types of structural isomerism
• 18 A buffer solution is prepared by dissolving 0.03,M phenol (C_6H_5OH) and 0.02,M sodium phenoxide (C_6H_5ONa) in 200,mL of water. Calculate the pH of the resulting solution at 25°C, given K_a(phenol)=1.3×10^-10. hard 5 marks Buffer pH calculation using Henderson–Hasselbalch
• 19 When 2‑methyl‑1‑butanol (CH_3CH(CH_3)CH_2CH_2OH) is oxidised with pyridinium chlorochromate (PCC), what is the major product? Provide its common name and its IUPAC name. medium 3 marks Oxidation of primary alcohols with PCC
• 20 During the dehydration of 3‑methyl‑2‑butanol (CH_3CH(OH)CH(CH_3)CH_3) in conc. H_2SO_4 at 170^circC, what is the major alkene product? Briefly explain the rationale. medium 3 marks Dehydration of alcohols, Zaitsev’s rule
• 21 Determine the “pKa” of phenol if its acid dissociation constant is “K_a=1.3×10^-10”. easy 1 mark Acid dissociation constant of phenol
• 22 Dehydration of 2‑methyl‑3‑butanol (CH_3CH(CH_3)CH(OH)CH_3) in conc. H_2SO_4 at 170^circmathrmC gives a major alkene product. Identify the product and explain the reasoning. medium 2 marks Dehydration of secondary alcohols – Zaitsev’s rule
• 23 1‑Phenylethanol (C_6H_5CH(OH)CH_3) is oxidised with pyridinium chlorochromate (PCC). Identify the major product and provide its common and IUPAC names. hard 3 marks Oxidation of secondary alcohols – PCC
• 24 A phenol derivative has an acid dissociation constant K_a = 2.5×10^-10 at 25°C. Calculate its pK_a. easy 1 mark pKa calculation using Ka
• 25 In a Williamson ether synthesis, which of the following pairs of reactants will directly give ethyl phenyl ether (C_2H_5OC_6H_5)? hard MCQ 3 marks Williamson ether synthesis – choice of reactants
• 26 Phenol has an acid dissociation constant K_a = 1.3×10^-10 at 25°C. Calculate its pK_a. easy 1 mark Acid dissociation constant of phenol
• 27 3-Pentanol (CH₃CH₂CH₂CH(OH)CH₃) is treated with conc. H_2SO_4 at 170°C. Identify the major alkene product formed and explain why it is favored. medium 3 marks Dehydration of alcohols (Zaitsev rule)
• 28 A buffer is prepared by dissolving 0.025 M phenol (C_6H_5OH) and 0.015 M sodium phenoxide (C_6H_5ONa) in water at 25°C. Given K_a(phenol)=1.3×10^-10, calculate the pH of the buffer. hard 5 marks Buffer pH calculation (Henderson–Hasselbalch)
• 29 Which of the following pairs of reactants will directly give ethyl phenyl ether (C_2H_5OC_6H_5) in a Williamson ether synthesis? hard MCQ 4 marks Williamson ether synthesis
• 30 2‑Methyl‑1‑butanol (CH_3CH(CH_3)CH_2CH_2OH) is heated with concentrated H_2SO_4 at 170°C. Predict the major alkene product formed, give its IUPAC name, and explain why it is favoured over other possible alkenes. hard 5 marks Acid‑catalysed dehydration – Zaitsev’s rule
• 31 Which pair of reactants will directly yield methyl phenyl ether (C_6H_5OCH_3) by the Williamson ether synthesis? easy MCQ 1 mark Williamson ether synthesis
• 32 The acid dissociation constant of p‑nitrophenol is K_a = 7.0 × 10^-8 at 25°C. Calculate its pK_a. medium 2 marks Acidity of phenols – $pK_a$ calculation
• 33 A buffer solution is prepared by mixing 0.040 M p‑nitrophenol and 0.025 M sodium p‑nitrophenoxide. Given K_a(p-nitrophenol) = 7.0 × 10^-8, calculate the pH of the buffer at 25°C. medium 3 marks Buffer calculation using Henderson–Hasselbalch