Aldehydes Ketones and Carboxylic Acids

34 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 'Aldehydes Ketones and Carboxylic Acids' (Class 12)? medium MCQ Reaction Mechanism & Bonding
• 2 What factor affects the rate or equilibrium constant of reactions in 'Aldehydes Ketones and Carboxylic Acids'? medium MCQ Chemical Kinetics & Factors
• 3 Which functional group or IUPAC nomenclature rule applies to compounds in 'Aldehydes Ketones and Carboxylic Acids'? medium MCQ IUPAC Nomenclature & Structure
• 4 What is the major product obtained in the characteristic reaction of 'Aldehydes Ketones and Carboxylic Acids'? medium MCQ Reaction Products & Selectivity
• 5 Which of the following products is obtained when cyclohexanone is treated with sodium borohydride (NaBH4) in ethanol? easy MCQ 1 mark Reduction of carbonyl compounds
• 6 2‑Propanol (CH3CHOHCH3) is oxidised by sodium dichromate (Na2Cr2O7·2H2O) in acidic medium to give acetone. If 5.0 g of 2‑propanol are used, how many moles of acetone will be formed assuming quantitative conversion? medium 2 marks Oxidation of secondary alcohols to ketones
• 7 Explain why acetone (CH3COCH3) gives a positive iodoform test when treated with aqueous iodine and sodium hydroxide. Write the step‑wise mechanism, including all intermediates, and state the final product formed. hard 5 marks Haloform (iodoform) reaction of methyl ketones
• 8 Calculate the pH of a 0.025 M solution of acetaldehyde (CH3CHO) at 25 °C, given that its α‑hydrogen acidity constant Ka = 1.0 × 10⁻¹⁷. medium 2 marks Acidity of α‑hydrogen in aldehydes
• 9 Write the balanced equation for the oxidation of ethanol to acetic acid using potassium dichromate in acidic medium. State the number of electrons transferred per mole of ethanol. medium 2 marks Redox stoichiometry in acid medium
• 10 Aldol condensation of acetaldehyde with itself in a 0.1 M NaOH solution produces a product. Which of the following is the major product? medium MCQ 3 marks Aldol condensation mechanism
• 11 A 0.025 M solution of acetic acid (Ka = 1.8×10⁻⁵) is prepared at 25 °C. Calculate the pH of the solution. medium 3 marks pH calculation for weak acids
• 12 Oxidise 1‑propanol to propionic acid using potassium dichromate in acidic medium. Write the balanced equation and state the number of electrons transferred per mole of 1‑propanol. easy 2 marks Oxidation of alcohol to carboxylic acid
• 13 Reduce methyl vinyl ketone (CH3C(O)CH=CH2) with sodium borohydride in ethanol at room temperature. Identify the major product, indicating the stereochemistry formed. hard 5 marks Reduction of α,β‑unsaturated ketones
• 14 Acetic acid reacts with excess ethanol in the presence of concentrated H₂SO₄ to give ethyl acetate (Fischer esterification). If 5.0 g of acetic acid are used, calculate the theoretical mass of ethyl acetate obtained. (Molar masses: CH₃COOH = 60.05 g mol⁻¹, CH₃COOC₂H₅ = 88.11 g mol⁻¹). hard 5 marks Fischer esterification and stoichiometry
• 15 Calculate the pH of a 0.10 M solution of formic acid (HCOOH, Ka = 1.8×10⁻⁴) at 25 °C. medium 2 marks pH of weak acid solution
• 16 Name the following compound according to IUPAC nomenclature: CH₃‑CH₂‑C(O)‑CH₃. easy 1 mark Nomenclature of ketones
• 17 When benzaldehyde (C₆H₅CHO) is treated with sodium borohydride (NaBH₄) in ethanol at room temperature, which product is formed? hard MCQ 3 marks Reduction of aldehydes with NaBH₄
• 18 A 0.050 M solution of isobutyric acid ((CH3)2CHCOOH, Ka = 1.9×10⁻⁵) is prepared at 25 °C. Calculate the pH of the solution. hard 5 marks pH calculation from acid dissociation constant
• 19 If 2.5 g of formic acid (M = 46.03 g mol⁻¹) reacts with excess methanol in the presence of concentrated H₂SO₄ to give methyl formate (M = 70.07 g mol⁻¹), calculate the theoretical mass of methyl formate obtained. medium 2 marks Fischer esterification stoichiometry
• 20 What is the major product when acetophenone (C6H5COCH3) is reduced with NaBH4 in ethanol? easy MCQ 1 mark Reduction of ketones to secondary alcohols
• 21 Explain the stereochemical outcome of the reduction of 2‑butanone (CH3COCH2CH3) with NaBH4 in ethanol. Identify the configuration of the newly formed chiral centre and draw the major product. hard 5 marks Stereochemistry of hydride reduction of ketones
• 22 A 4.0 g sample of acetic acid is esterified with excess ethanol in the presence of concentrated H₂SO₄ to give ethyl acetate. Calculate the theoretical mass of ethyl acetate that can be formed. (Molar mass CH₃COOH = 60.05 g mol⁻¹, CH₃COOC₂H₅ = 88.11 g mol⁻¹.) medium 2 marks Fischer esterification yield calculation
• 23 Write the balanced equation for the oxidation of 1‑propanol (CH₃CH₂CH₂OH) to propionic acid (CH₃CH₂COOH) using potassium dichromate (K₂Cr₂O₇) in acidic medium. State the number of electrons transferred per mole of 1‑propanol and calculate the mass of propionic acid obtained from 5.0 g of 1‑propanol assuming quantitative conversion. (Molar mass 1‑propanol = 60.10 g mol⁻¹; propionic acid = 74.08 g mol⁻¹.) hard 5 marks Redox stoichiometry and electron count
• 24 Calculate the pH of a 0.010 M solution of acetic acid (CH₃COOH) at 25 °C. Ka = 1.8×10⁻⁵. easy 1 mark Acid dissociation and pH calculation
• 25 Calculate the pH of a 0.020 M solution of formic acid (HCOOH) at 25 °C. Ka = 1.8×10⁻⁴. easy 1 mark pH of weak acid solution
• 26 Which product is obtained when benzophenone (C₆H₅COC₆H₅) is reduced with NaBH₄ in ethanol? medium MCQ 3 marks reduction of ketone to secondary alcohol
• 27 A 6.0 g sample of propanoic acid (CH₃CH₂COOH) reacts with excess methanol in the presence of concentrated H₂SO₄ to form methyl propanoate. What is the theoretical mass of methyl propanoate that can be formed? (Molar mass of propanoic acid = 74.08 g mol⁻¹; methyl propanoate = 100.12 g mol⁻¹). medium 3 marks esterification yield calculation
• 28 What is the pH of a 0.020 M solution of propanoic acid (CH₃CH₂COOH) at 25 °C? Ka = 1.8×10⁻⁵. easy 1 mark pH of weak carboxylic acid
• 29 Write the balanced equation for the oxidation of 2‑pentanol (CH₃CH₂CH(OH)CH₂CH₃) to 2‑pentanone (CH₃CH₂COCH₂CH₃) using potassium permanganate in alkaline medium. State the number of electrons transferred per mole of 2‑pentanol. hard 5 marks oxidation of secondary alcohols with KMnO₄
• 30 Write the balanced equation for the oxidation of 1‑phenylethanol (C6H5CH(OH)CH3) to acetophenone (C6H5COCH3) using potassium permanganate (KMnO4) in alkaline medium. State the number of electrons transferred per mole of 1‑phenylethanol and calculate the mass of acetophenone obtained from 8.0 g of 1‑phenylethanol assuming quantitative conversion. (Molar mass of 1‑phenylethanol = 120.15 g mol⁻¹; acetophenone = 120.15 g mol⁻¹). hard 5 marks Oxidation of secondary alcohol to ketone with KMnO4
• 31 In a Fischer esterification, 3.0 g of benzoic acid (C6H5COOH) reacts with excess ethanol to form methyl benzoate (C6H5COOCH3). Calculate the theoretical mass of methyl benzoate obtained. medium 4 marks Fischer esterification stoichiometry
• 32 Which product is obtained when cyclohexanone is treated with sodium borohydride (NaBH4) in ethanol? medium MCQ 3 marks Reduction of ketone to secondary alcohol
• 33 When benzaldehyde (C6H5CHO) is reduced with sodium borohydride in ethanol, which product is obtained? easy MCQ 1 mark Reduction of aldehydes
• 34 Calculate the pH of a 0.025 M solution of acetic acid (CH3COOH) at 25 °C, given its acid dissociation constant Ka = 1.8×10⁻⁵. hard 4 marks pH calculation for weak acids