Aldehydes & Ketones: Named Reactions — Practice Questions

Free NEET Chemistry multiple-choice questions on Aldehydes & Ketones: Named Reactions. Attempt each question and reveal the answer with a full explanation.

The oxidation of toluene to benzaldehyde by chromyl chloride ( CrO 2Cl 2 ) is called: Etard reaction Stephen reaction Cannizzaro reaction Wurtz-Fittig reaction The catalyst used in the Rosenmund reduction is: Pd/BaSO 4 LiAlH 4 NaBH 4 Sn/HCl Which of the following statements about the 'Aldol Condensation' is incorrect? It is only given by aldehydes with no -hydrogens It is catalyzed by dilute alkali It involves the formation of a -hydroxy aldehyde or ketone Dehydration of the aldol product gives an , -unsaturated carbonyl The reaction CH 3COCH 3 + 4[H] Zn-Hg/conc. HCl CH 3CH 2CH 3 + H 2O is an example of: Clemmensen reduction Wolff-Kishner reduction Rosenmund reduction Stephen's reduction Which of the following gives an aldol condensation reaction? CH 3CH 2CHO HCHO C 6H 5CHO (CH 3) 3CCHO Reduction of an aldehyde using Zn-Hg and concentrated HCl is called: Clemmensen reduction Wolff-Kishner reduction Stephen reduction Rosenmund reduction Identify the compound that will not give a positive Tollens' test but will give a positive Iodoform test. Acetone Acetaldehyde Benzaldehyde Formaldehyde The product 'P' in the reaction: CH 3COCl H 2/Pd-BaSO 4 P is: CH 3CHO CH 3CH 2OH CH 3COOH CH 3CH 3 Reduction of aldehydes and ketones into hydrocarbons using zinc amalgam and conc. HCl is called Cope reduction Dow reduction Wolf-Kishner reduction Clemmensen reduction. The product formed in Aldol condensation is a beta-hydroxy aldehyde or a beta-hydroxy ketone an alpha-hydroxy aldehyde or ketone an alpha, beta unsaturated ester a beta-hydroxy acid Which of the following will not undergo the Aldol condensation? Trichloroacetaldehyde Acetaldehyde Acetone Propanal What is the product formed when benzaldehyde reacts with concentrated NaOH solution? Sodium benzoate and Benzyl alcohol Sodium benzoate and Benzene Benzyl alcohol and Phenol Cinnamic acid In the Wolf-Kishner reduction, the carbonyl compound is heated with which of the following sets of reagents? NH 2NH 2 and KOH in ethylene glycol Zn-Hg and conc. HCl LiAlH 4 in dry ether H 2 and Pd-BaSO 4 Reaction of benzene with CO and HCl in the presence of anhydrous AlCl 3 to form benzaldehyde is known as: Gatterman-Koch reaction Etard reaction Stephen reaction Friedel-Crafts acylation According to Popoff's rule, during the oxidation of an unsymmetrical ketone like pentan-2-one with a strong oxidizing agent, the cleavage of the C-C bond occurs such that: The carbonyl group stays with the smaller alkyl group The carbonyl group stays with the larger alkyl group The carbonyl group is converted to CO 2 The alkyl groups are symmetric Which of the following compounds will NOT reduce Fehling's solution? Benzaldehyde Acetaldehyde Glucose Fructose The reaction of acetone with Ba(OH) 2 gives: Diacetone alcohol Mesityl oxide Phorone Mesitylene An organic compound with molecular formula C 3H 6O does not give a silver mirror with Tollens' reagent but forms an oxime with hydroxylamine. The compound is: Acetone Propanal Allyl alcohol Methyl ethyl ether What is the product formed when m -chlorobenzaldehyde is treated with 50 % KOH solution? m -Chlorobenzyl alcohol and Potassium m -chlorobenzoate m -Chlorobenzoic acid m -Chlorobenzyl alcohol Benzene and m -Chlorophenol Identify the compound 'X' in the reaction: X + H 2 → (Pd-BaSO 4/S) → CH 3CHO . Acetyl chloride Acetaldehyde Acetic acid Ethanol Which of the following can distinguish between Pentan-2-one and Pentan-3-one? Iodoform test Tollens' reagent Fehling's solution Lucas reagent The catalyst used in the Tischenko reaction is: Aluminum ethoxide Aluminum chloride Sodium ethoxide Dry HCl Which of the following compounds will give a positive Fehling's test? Ethanal Benzaldehyde Acetone Acetophenone Which among the following compounds will give a positive silver mirror test with Tollens' reagent but will not give a positive Fehling's test? Benzaldehyde Acetaldehyde Formaldehyde Glucose Reaction of propene with cold, dilute, alkaline KMnO 4 (Baeyer's reagent) yields: Propane-1,2-diol Propan-1-ol Propanal Propanoic acid Which of the following products is formed when 4-oxopentanoic acid is treated with Zn-Hg/HCl ? Pentanoic acid Pentan-1-ol Pentane 4-hydroxypentanoic acid The Perkin reaction involves the condensation of an aromatic aldehyde with: An aliphatic acid anhydride in the presence of its sodium salt An aliphatic ketone in the presence of dilute NaOH An ester in the presence of sodium ethoxide An acid chloride in the presence of pyridine In the Baeyer-Villiger oxidation of acetophenone ( C 6H 5COCH 3 ) using peroxyacetic acid, the major product is: Phenyl acetate Methyl benzoate Benzoic acid Acetophenone oxide Dry distillation of a mixture of calcium acetate and calcium formate yields: Ethanal Propanone Methanal Ethanol In the reaction CH 3CHO + NH 2NH 2 KOH/Ethylene glycol, X , the product 'X' is: Ethane Ethanol Ethanoic acid Hydrazone Acetone reacts with SeO 2 (selenium dioxide) to form which of the following compounds? Methylglyoxal Glyoxal Acetic acid Oxalic acid When benzaldehyde reacts with acetone in the presence of dilute NaOH , the major organic product formed is: 4-phenylbut-3-en-2-one 1-phenylbut-1-en-3-one Benzalacetone Dibenzalacetone What is the product 'B' in the following sequence? CH 3COOH PCl 5 A C 6H 6 / Anh. AlCl 3 B . Acetophenone Benzophenone Benzaldehyde Ethyl benzene The reaction 2HCHO + NaOH (conc.) → CH 3OH + HCOONa is an example of: Disproportionation reaction Addition reaction Elimination reaction Substitution reaction In the reaction R-COCl + H 2 Pd-BaSO 4 R-CHO , the use of BaSO 4 is to: Poison the catalyst to stop the reduction at the aldehyde stage Act as a promoter for the catalyst Remove HCl formed in the reaction Increase the surface area of Pd When ethanol is treated with bleaching powder, the final organic product obtained is: Chloroform Acetaldehyde Ethyl chloride Chloral When 4-oxopentanoic acid is treated with NH 2NH 2/KOH in ethylene glycol at high temperature, the product is: Pentanoic acid Pentan-2-ol Butanoic acid Pentane The reaction of cyclohexanone oxime with concentrated H 2SO 4 followed by heating is a key step in the synthesis of Nylon-6. This rearrangement is known as: Beckmann rearrangement Fries rearrangement Claisen rearrangement Curtius rearrangement The conversion of R-COCl to R-CHO using H 2/Pd-BaSO 4 is poisoned by sulfur or quinoline to: Prevent further reduction of aldehyde to alcohol Increase the rate of reaction Increase the yield of the acid chloride Make the catalyst more active A mixture of benzaldehyde and formaldehyde on heating with concentrated NaOH solution gives: Benzyl alcohol and sodium formate Sodium benzoate and methanol Benzyl alcohol and methanol Sodium benzoate and sodium formate Which of the following will not undergo the iodoform test? Pentan-3-one Ethanol Acetone Isopropyl alcohol Which of the following will not undergo Cross-Cannizzaro reaction with formaldehyde? Acetaldehyde Benzaldehyde Trimethylacetaldehyde Chloral Which one of the following on treatment with 50% aqueous sodium hydroxide yields the corresponding alcohol and acid? C6H5CHO CH3CH2CH2CHO CH3 - O | C - CH3 C6H5CH2CHO Reaction by which Benzaldehyde cannot be prepared? + CrO2Cl2 in CS2 followed by H3O+ + H2 in presence of Pd-BaSO4 + CO + HCl in presence of anhydrous AlCl3 + Zn/Hg and conc. HCl Which of the following does not give a silver mirror with Tollens' reagent? Acetone Acetaldehyde Formaldehyde Benzaldehyde Consider the following sequence of reactions : The substance ‘B’ is Acetone Benzene Acetophenone Benzaldehyde Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as Cannizzaro’s reaction Cross Cannizzaro’s reaction Cross Aldol condensation Aldol condensation Identify product (A) in the following reaction: Identify the major product obtained in the following reaction: Predict the product formed in a 'Cross-Cannizzaro' reaction between benzaldehyde and formaldehyde in the presence of concentrated NaOH . Benzyl alcohol and Sodium formate Sodium benzoate and Methanol Benzyl alcohol and Methanol Sodium benzoate and Sodium formate Identify the product 'Z' in the sequence: Benzene → (CH 3COCl/AlCl 3) → X → (Zn-Hg/HCl) → Y → (KMnO 4/OH -, Δ) → Z . Benzoic acid Acetophenone Ethylbenzene Benzaldehyde Predict the product of the reaction between benzaldehyde and acetophenone in the presence of dilute NaOH . 1,3-Diphenylprop-2-en-1-one 1,3-Diphenylpropan-1-ol Benzoin Benzyl acetate How many total Aldol condensation products (including structural and stereoisomers) are possible from a mixture of ethanal and propanal? 4 structural products 2 products 1 product 6 products Acetone reacts with selenium dioxide ( SeO 2 ) to produce: Methylglyoxal Glyoxal Acetic acid Acetaldehyde The reaction of 2,3-dimethylbutane-2,3-diol with concentrated H 2SO 4 yields which of the following compounds as the major product? 3,3-dimethylbutan-2-one 2,3-dimethylbut-1-ene 2,3-dimethylbut-2-ene 3-methylpentan-2-one Identify the compound that will not give a positive iodoform test among the following: 3-pentanone 2-pentanone Ethanol Acetophenone The Beckmann rearrangement of acetophenone oxime in the presence of PCl 5 primarily yields: Acetanilide N-methylbenzamide Benzanilide Acetamide In the Etard reaction, toluene is oxidized to benzaldehyde using chromyl chloride. The reaction proceeds through an intermediate complex. What is the formula of this complex? C 6H 5CH(OCrOHCl 2) 2 C 6H 5CH 2OCrCl 2 C 6H 5CrO 2Cl 2 C 6H 5CHO CrO 2Cl 2 When acetone is treated with dry HCl gas, it undergoes self-condensation to form a linear trimer known as: Phorone Mesityl oxide Mesitylene Diacetone alcohol The rate-determining step in the Cannizzaro reaction is: The transfer of hydride ion ( H - ) The attack of OH - on the carbonyl carbon The deprotonation of the alcohol The protonation of the carboxylate ion When methanoic acid ( HCOOH ) is heated with Tollens' reagent, it gives a silver mirror. This is because: It contains an aldehyde-like hydrogen attached to the carbonyl group It is a very strong acid It is a dicarboxylic acid It contains a peroxide linkage Reaction of Acetone with Aluminum isopropoxide in Isopropanol is known as: Meerwein-Ponndorf-Verley reduction Oppenauer oxidation Clemmensen reduction Sabatier-Senderens reaction Which one of the following is not formed when acetone reacts with 2-pentanone in the presence of dilute NaOH followed by heating? For the following reaction sequence, choose the correct option. If P is the sodium salt of a carboxylic acid, Q is a primary alcohol P and Q are aromatic compounds If P gives a carboxylic acid on acidification, Q gives a poisonous gas on exposure to air and light Both P and Q are carbonyl compounds The compound that CANNOT be obtained from the aldol condensation reaction shown below, is An organic compound 'A' ( C 2H 4O ) on oxidation gives 'B' ( C 2H 4O 2 ). 'A' also undergoes iodoform test. 'A' is: Acetaldehyde Ethanol Formaldehyde Acetone Which of the following will not undergo the Cannizzaro reaction? Acetaldehyde Benzaldehyde Formaldehyde Trimethylacetaldehyde The major product formed by the reaction of benzoyl chloride with H 2 in the presence of Pd-BaSO 4 is: Benzaldehyde Benzyl alcohol Benzoic acid Toluene