CBSE Class 12 Chemistry Aldehydes Ketones and Carboxylic Acids MCQs Set 03

Question. The product formed in aldol condensation is
(a) a beta-hydroxy aldehyde or a beta-hydroxy ketone
(b) an alpha-hydroxy aldehyde or ketone
(c) an alpha, beta unsaturated ester
(d) a beta-hydroxy acid.

Answer : A

Question. Which of the following can be used to differentiate between aldehyde and ketone?
(a) Ammoniacal AgNO₃
(b) Ammoniacal AgNO₃ in the presence oftartarate ion
(c) I₂ in the presence of base
(d) Ammoniacal AgNO₃ in the presence of citrate ion

Answer : A

Question. A compound X undergoes reduction with LiAIH₄ to yield Y . When vapours of Yare passed over freshly reduced copper at 300° C, X is formed. What is Y? 
(a) CH₃COCH₃
(b) CH₃CHO
(c) CH₃CH₂OH
(d) CH₃OCH₃

Answer : C

Question. The product formed in the aldol condensation of acetaldehyde is
(a) CH₃CH₂CH(OH)CHO
(b) CH₃CH(OH)CH₂CHO
(c) CH₃CH(OH)COCH₃
(d) CH₃CH₂CH₂CHO 

Answer : B

Question. The reaction of an organic compound with ammonia followed by nitration of the product gives a powerful explosive, called RDX. The organic compound is
(a) phenol
(b) toluene
(c) glycerine
(d) formaldehyde

Answer : D

Question. The reagent which can be used to distinguish acetophenone from benzophenone is
(a) 2,4-dinitrophenylhydrazine
(b) aqueous solution of NaHSO3
(c) Benedict reagent
(d) I2 and NaOH.

Answer : D

Question. If formaldehyde and KOH are heated, then we get
(a) methane
(b) methyl alcohol
(c) ethyl formate
(d) acetylene.

Answer : B

Question. Which of the following compounds gives benzoic acid on hydrolysis?
(a) Chlorobenzene
(b) Benzoyl chloride
(c) Chlorophenol
(d) Chlorotoluene

Answer : B

Question. Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their
(a) formation of intramolecular H-bonding
(b) formation of carboxylate ion
(c) more extensive association of carboxylic acid via van der Waals’ forces of attraction
(d) formation of intermolecular H-bonding.

Answer : D

Question. The correct order of decreasing acid strength of trichloroacetic acid (A), trifluoroacetic acid (B), acetic acid (C) and formic acid (D) is
(a) B > A > D > C
(b) B > D > C > A
(c) A > B > C > D
(d) A > C > B > D

Answer : A

Question. Which of the following does not give Fehling solution test?
(a) Acetone
(b) Propanal
(c) Ethanal
(d) Butanal

Answer : A

Question. Aldo! condensation is given by
(a) trimethyl acetaldehyde
(b) acetaldehyde
(c) benzaldehyde
(d) formaldehyde

Answer : B

Question. Which of the following will form two isomers with semi carbazide ?
(a) Benzaldehyde
(b) Acetone
(c) Benzoquinone
(d) Benzophenone

Answer : A

Question. In the reaction
CH₃COOH →^LiAIH₄ A →^PCl₅ B →^Ale.KOH C, the product C is 
(a) acetaldehyde
(b) acetylene
(c) ethylene
(d) acetyl chloride

Answer : C

Question. A liquid was mixed with ethanol and a drop of concentrated H₂SO₄ was added. A compound with a fruity smell was formed. The liquid was 
(a) CH₃OH
(b) HCHO
(c) CH₃COCH₃
(d) CH₃COOC₂H₅ 

Answer : D

Question. Consider the reaction : RCHO + NH₂NH₂ → RCH=N — NH₂ What sort of reaction is it?
(a) Electrophilic addition-elimination reaction
(b) Free radical addition-elimination reaction
(c) Electrophilic substitution-elimination reaction
(d) Nucleophilic addition-elimination reaction

Answer : D

Question. Which of the following compounds will give a myellow precipitate with iodine and alkali?
(a) Acetophenone
(b) Methyl acetate
(c) Acetamide
(d) 2-Hydroxypropane

Answer : A, D

Question. Clemmensen reduction of a ketone is carried out in the presence of which of the following?
(a) Glycol with KOH
(b) Zn-Hg with HCl
(c) LiAlH₄
(d) H₂ and Pt as catalyst

Answer : B

Question. Which of the following reactions will not result in the formation of carbon-carbon bonds?
(a) Reimer–Tiemann reaction
(b) Cannizzaro reaction
(c) Wurtz reaction
(d) Friedel–Crafts acylation

Answer : B

Question. A strong base can abstract an a-hydrogen from
(a) ketone
(b) alkane
(c) alkene
(d) amine.

Answer : A

Question. Reduction of aldehydes and ketones into hydrocarbons using zinc amalgam and conc. HCl is called
(a) Cope reduction
(b) Dow reduction
(c) Wolff–Kishner reduction
(d) Clemmensen reduction.

Answer : D

Question. 2-pentanone and 3-petanone can be distinguished by
(a) Cannizzaro’s reaction
(c) Iodoform reaction reduction
(b) Aldo! condensation
(d) Clemmensen’s

Answer : C

Question. The correct increasing order of the acid strength ofbenzoic acid (I), 4-nitrobenzoic acid (II), 3, 4-dinitrobenzoic acid (III) and 4methoxybenzoic acid (IV) is
(a) I < II < III < IV
(b) II < I < IV < III
(c) IV < I < II < III
(d) IV < II < I < III
(e) I < IV < II < III

Answer : C

Question. Polarisation in acrolein can be described as
(a) ^+δCH₂=CH — ^+δCHO
(b) ^-δCH₂₌ CH — ^+δCHO 
(c) ^-δCH₂₌ CH — CHO^+δ 
(d) ^+δCH= CH — CHO^-δ

Answer : D

Question. Which acid is present in vinegar?
(a) Formic acid
(b) Acetic acid
(c) Butyric acid
(d) Tartaric acid

Answer : B

Question. What product is formed when cyclohexanone is oxidised?
(a) HOOC. (CH₂)₄ · COOH 
(b) CH₃CH₂COOH
(c) CH₃(CH₂)₄COOH
(d) None of the options

Answer : A

Question. Which of the following is incorrect?
(a) FeCl3 is used in detection of phenol.
(b) Fehling solution is used in detection of glucose.
(c) Tollens’ reagent is used in detection of unsaturation.
(d) NaHSO3 is used in detection of carbonyl compound.

Answer : C

Question. Acetaldehyde reacts with
(a) electrophiles only
(b) nucleophiles only
(c) free radicals only
(d) both electrophiles and nucleophiles.

Answer : B