Aldehydes & Ketones: Nucleophilic Addition — Practice Questions

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

Isopropyl alcohol on treatment with K 2Cr 2O 7 / H 2SO 4 gives: Acetone Acetaldehyde Propanoic acid Ethanoic acid The reaction of nitriles ( R-CN ) with DIBAL-H followed by hydrolysis yields: Aldehydes Ketones Carboxylic acids Primary alcohols What is the product obtained by the reaction of formaldehyde with CH 3MgBr followed by hydrolysis? Ethanol Methanol Propan-2-ol Propan-1-ol Reduction of benzoyl chloride with H 2/Pd-BaSO 4 produces benzaldehyde. What is the role of BaSO 4 in this reaction? Catalytic poison to prevent further reduction to alcohol Dehydrating agent Oxidizing agent Reducing agent What is the product obtained when C 6H 5CHO reacts with NH 2OH ? C 6H 5CH=NOH C 6H 5CH 2NH 2 C 6H 5CONH 2 C 6H 5NH 2 Nucleophilic addition reaction will be most favoured in:- CH3 - CH2 - CH2 - O | C - CH3 (CH3)2C=O CH3CH2CHO CH3CHO The product formed by the reaction of an aldehyde with a primary amine is :- Schiff base Ketone Carboxylic acid Aromatic acid Reaction between acetone and methylmagnesium chloride followed by hydrolysis will give : Sec. butyl alcohol Tert. butyl alcohol Isobutyl alcohol Isopropyl alcohol Match List-I with List-II. array ll List – I; (Products formed) & List – II; (Reaction of carbonyl compound with) (a) Cyanohydrin & (i) NH2OH (b) Acetal & (ii) RNH2 (c) Schiff's base & (iii) alcohol (d) Oxime & (iv) HCN array Choose the correct answer from the options given below (a) – (ii), (b) – (iii), (c) – (iv), (d) – (i) (a) – (i), (b) – (iii), (c) – (ii), (d) – (iv) (a) – (iv), (b) – (iii), (c) – (ii), (d) – (i) (a) – (iii), (b) – (iv), (c) – (ii), (d) – (i) Given below are two statements : Statement I : The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses because of weak molecular association in aldehydes and ketones due to dipole - dipole interactions. Statement II : The boiling points of aldehydes and ketones are lower than the alcohols of similar molecular masses due to the absence of H-bonding. In the light of the above statements, choose the most appropriate answer from the given below Both Statement I and Statement II are incorrect Statement I is correct but Statement II is incorrect Statement I is incorrect but Statement II is correct Both Statement I and Statement II are correct Identify the product 'X' in the following reaction: CH 3MgBr + CO 2 Dry Ether Y H 3O + X . CH 3COOH CH 3CHO CH 3CH 2OH HCOOCH 3 Which of the following is used as a flavoring agent in the food industry and has the smell of bitter almonds? Benzaldehyde Acetaldehyde Acetone Formaldehyde Which among the following is most reactive towards nucleophilic addition? HCHO CH 3CHO CH 3COCH 3 CH 3CH 2CHO The reaction of CH 3CHO with HCN followed by hydrolysis gives: Lactic acid Tartaric acid Glycolic acid Acetic acid Reaction of methyl magnesium iodide with acetone followed by hydrolysis gives: 2-Methylpropan-2-ol Propan-2-ol Butan-2-ol Butan-1-ol Which of the following will reduce R-CN to R-CHO ? SnCl 2 / HCl followed by H 3O + LiAlH 4 followed by H 2O NaBH 4 in ethanol H 2 / Ni What is the product of the reaction between chloral ( CCl 3CHO ) and chlorobenzene in the presence of concentrated H 2SO 4 ? DDT Gammexane Freon Chloropicrin Which reagent is used for the selective reduction of an ester to an aldehyde? DIBAL-H LiAlH 4 NaBH 4 H 2 / Pd The reaction of an aldehyde with a primary amine forms: Schiff's base Enamine Oxime Hydrazone The reaction of formaldehyde with CH 3MgBr followed by hydrolysis gives: Ethanol Methanol Propan-2-ol Propan-1-ol Urotropine is formed by the reaction of ammonia with: Formaldehyde Acetaldehyde Acetone Benzaldehyde Reaction of ethylene oxide with CH 3MgBr followed by hydrolysis yields: Propan-1-ol Propan-2-ol Ethanol Ethane Schiff's reagent gives a pink color with: Aldehydes Ketones Ethers Carboxylic acids Benzoin condensation involves the treatment of benzaldehyde with: Ethanolic KCN Aqueous NaOH Ethanolic KOH Zn-Hg/HCl The reaction of propene with mercuric acetate followed by reduction with NaBH 4 (Oxymercuration-Demercuration) yields: Propan-2-ol Propan-1-ol Propane-1,2-diol Propanone Glycerol when heated with potassium bisulfate ( KHSO 4 ) yields an unpleasant smelling compound 'A'. 'A' is: Acrolein Acrylic acid Allyl alcohol Acetone The reagent NaBH 4 is used to reduce crotonaldehyde ( CH 3-CH=CH-CHO ). The product formed is: But-2-en-1-ol Butan-1-ol Butan-2-ol But-2-en-2-ol The Reformatsky reaction involves the reaction of an aldehyde or ketone with an -halo ester in the presence of which metal? Zinc Magnesium Lithium Copper In the nucleophilic addition of HCN to a carbonyl compound, the rate-determining step is: The attack of CN - on the carbonyl carbon The protonation of the carbonyl oxygen The dissociation of HCN to H + and CN - The formation of the O-H bond Which of the following is the correct order of decreasing reactivity towards nucleophilic addition? ClCH 2CHO > CH 3CHO > CH 3COCH 3 CH 3CHO > ClCH 2CHO > CH 3COCH 3 CH 3COCH 3 > CH 3CHO > ClCH 2CHO CH 3CHO > CH 3COCH 3 > ClCH 2CHO What is the product of the reaction of Ethyl acetate with excess CH 3MgBr followed by hydrolysis? 2-methylpropan-2-ol Propan-2-ol Ethanol Acetone The order of reactivity of the following toward nucleophilic addition is: (I) HCHO , (II) CH 3CHO , (III) C 6H 5CHO , (IV) CH 3COCH 3 . I > II > III > IV I > II > IV > III IV > III > II > I III > IV > II > I Reaction of ethyl acetate with excess of CH 3MgBr followed by hydrolysis yields: 2-methylpropan-2-ol Propan-2-ol Acetone Butan-2-ol Aldehydes and methyl ketones react with saturated sodium bisulfite ( NaHSO 3 ) solution to form: Crystalline bisulfite addition compounds Liquid esters Gaseous hydrocarbons Solid carboxylic acids Acetone reacts with ethylene glycol in the presence of dry HCl gas to form a cyclic product. This product is classified as a: Cyclic ketal Cyclic acetal Hemiacetal Hemiketal When glycerol ( CH 2OH-CHOH-CH 2OH ) is treated with an excess of periodic acid ( HIO 4 ), the products formed are: Two moles of HCHO and one mole of HCOOH Three moles of HCOOH Three moles of HCHO One mole of HCHO and two moles of HCOOH The increasing order of the rate of nucleophilic addition to the following compounds is: (I) HCHO , (II) CH 3CHO , (III) CH 3COCH 3 , (IV) PhCOCH 3 . IV < III < II < I I < II < III < IV III < IV < II < I IV < III < I < II The reaction of acetone with chloroform in the presence of potassium hydroxide ( KOH ) yields a compound used as a hypnotic drug. Identify the compound. Chloretone Chloral Chloroform Acetone hydrate Among the following, which will have the highest value of dipole moment? CH 3CHO CH 3OCH 3 CH 3CH 2OH CH 3CH 2CH 3 The reaction of CH 3CN with CH 3MgBr followed by hydrolysis yields: Acetone Acetaldehyde Ethylamine Acetic acid The formation of an acetal from an aldehyde involves the reaction with: Two molecules of an alcohol in the presence of dry HCl gas One molecule of an alcohol in the presence of NaOH Two molecules of an alcohol in the presence of NaOH One molecule of an alcohol in the presence of dry HCl gas In the reaction CH 3CHO + HCN A H 2O/H + B , the compound B is: Lactic acid Malonic acid Glycolic acid Propionic acid The major organic product formed from the following reaction is - In a set of reactions acetic acid yielded a product D The structure of D would be - The relative reactivity of formaldehyde (HCHO), acetaldehyde ( CH 3CHO ), and acetone ( CH 3COCH 3 ) towards nucleophilic addition follows the order: HCHO > CH 3CHO > CH 3COCH 3 CH 3COCH 3 > CH 3CHO > HCHO CH 3CHO > HCHO > CH 3COCH 3 HCHO > CH 3COCH 3 > CH 3CHO A carbonyl compound reacts with hydrogen cyanide to form cyanohydrin which on hydrolysis forms a racemic mixture of -hydroxy acid. The carbonyl compound is: Acetaldehyde Acetone diethyl ketone Formaldehyde Which one is most reactive towards Nucleophilic addition reaction? What is the IUPAC name of the organic compound formed in the following chemical reaction? Acetone [ (ii) H2O, H+ ] (i) C2H5MgBr , dry Ether Product pentan-2-ol pentan-3-ol 2-methylbutan-2-ol 2-methylpropan-2-ol The product formed in the following chemical reaction is: Complete the following reaction [C] is Arrange the following in increasing order of reactivity towards nucleophilic addition: Acetone (I), Benzaldehyde (II), Formaldehyde (III), Acetaldehyde (IV). I < II < IV < III II < I < IV < III I < IV < II < III III < IV < II < I The reaction of benzaldehyde with PCl 5 yields: Benzal chloride Benzoyl chloride Benzyl chloride Chlorobenzene Which of the following will be the major product when methyloxirane reacts with CH 3MgBr followed by hydrolysis? Pentan-2-ol Butan-2-ol 2-methylpropan-2-ol Butan-1-ol Nucleophilic addition of ammonia derivatives ( NH 2-Z ) to aldehydes and ketones is highly dependent on pH . The reaction rate is maximum at approximately which pH ? 3.5 1.0 7.0 10.0 The reduction of cinnamaldehyde ( C 6H 5-CH=CH-CHO ) using LiAlH 4 produces: C 6H 5-CH=CH-CH 2OH C 6H 5-CH 2-CH 2-CH 2OH C 6H 5-CH 2-CH 2-CHO C 6H 5-CH 2-CH 2-CH 3 Partial hydrolysis of acetonitrile ( CH 3CN ) with cold concentrated HCl gives: Acetamide Acetic acid Ethylamine Ammonium acetate Which of the following compounds has the highest enol content in its pure liquid state? Acetylacetone ( CH 3COCH 2COCH 3 ) Acetone Acetaldehyde Ethyl acetate Formaldehyde polymerizes to form a white solid known as 'Paraformaldehyde'. However, when it is distilled with dilute H 2SO 4 , it forms a cyclic trimer called: Metaformaldehyde (Trioxane) Paraldehyde Metaldehyde Formalin The reaction of propylene oxide (methyloxirane) with CH 3MgBr followed by hydrolysis yields: Butan-2-ol Butan-1-ol 2-Methylpropan-2-ol 2-Methylpropan-1-ol When benzaldehyde reacts with ammonia, the product formed is a crystalline solid known as: Hydrobenzamide Benzalimines Benzamide Urotropine In the reaction of an aldehyde with NaHSO 3 , the nucleophile attacking the carbonyl carbon is: SO 3 2- (via sulfur atom) HSO 3 - (via oxygen atom) OH - Na + Which of the following reagents is specifically used for the 'Swern Oxidation' of alcohols to aldehydes or ketones? Oxalyl chloride and DMSO PCC KMnO 4 LiAlH 4 Identify the product 'X' in the reaction: CH 3CHO + 3HCHO Ca(OH) 2 X HCHO/OH - Pentaerythritol . (HOCH 2) 3CCHO CH 3C(OH) 3 CH 3CH 2CHO (HOCH 2) 2CHCHO The reaction of propanal with SeO 2 (Selenium dioxide) results in the formation of: 2-Oxopropanal Propan-1-ol Propanoic acid 1,2-Propanediol The major product of the following reaction is Compound P( C8H8O ) gives a red orange precipitate with 2,4-DNP reagent and it does not reduce Fehling’s reagent. On drastic oxidation with chromic acid, P gives an aromatic product Q that produces effervescence on treating with aq. NaHCO3 . Compounds P and Q, respectively, are : The catalyst used in Stephen's reduction for converting nitriles to aldehydes is: SnCl 2 / HCl Pd-BaSO 4 LiAlH 4 H 2 / Ni Consider the following reaction, and choose the correct option. On treating compound P with saturated NaHCO3 solution, brisk effervescence is observed Compound P can be prepared by treating benzene with anhydrous AlCl3 and CH3COCl On treatment with bromine water, compound P gives a white precipitate Compound P is obtained by the hydrogenation of benzoyl chloride with Pd on BaSO4 The formation of a Cyanohydrin from a ketone is an example of: Nucleophilic addition Electrophilic addition Nucleophilic substitution Electrophilic substitution The reaction of an aldehyde with one equivalent of an alcohol in the presence of dry HCl gas yields: Hemiacetal Acetal Ester Ether