CBSE Class 12 Chemistry Aldehydes Ketones and Carboxylic Acids MCQs Set 04

Question: Formalin is the commercial name of
(a) formic acid
(b) fluroform
(c) 40% aqueous solution of methanal
(d) para-formaldehyde
Answer: c 

Question: Which does not react with Fehling's solution?
(a) CH₃CHO
(b) C₆H₅CHO 
(c) C₆H₁₂O₆
(d) HCOOH
Answer: b 

Question: Cross aldol condensation occurs between
(a) two same aldehydes
(b) two same ketones
(c) two different aldehydes and ketones
(d) None of the above
Answer: c

Question: Which reaction, intermediate is formed during the condensation reaction between acetaldehyde and formaldehyde? 
(a) : ^-CH₂CHO
(b) ⁺CH₂CHO
(c) ⁺CH₂OH
(d) : ^-CHCHO
Answer: a 

Question: Benzyl alcohol and sodium benzoate is obtained by the action of sodium hydroxide on benzaldehyde. This reaction is known as
(a) Perkin's reaction
(b) Cannizzaro's reaction
(c) Sandmeyer's reaction
(d) Claisen condensation
Answer: b 

Question: An organic compound of molecular formula C₃H₆O did not give a silver mirror with Tollen 's reagent, but gave an oxime with hydroxylarnine, it may be
(a) CH₃—CO—CH₃
(b) C₂H₅CHO
(c) CH₂ = CH—CH₂—OH
(d) CH₃—O—CH = CH₂ 
Answer: a

Question: Which of the following acids dissociates to the greatest extent in aqueous solution? 
(a) Trichloroacetic acid
(b) Acetic acid
(c) Chloroacetic acid
(d) Dichloroacetic acid 
Answer: a 

Question: CH₃COOH →^Br₂/P Y→^{(i) KC}_(ii)H3O⁺ X. Here, X is
(a) glycollic acid
(b) α-hydroxy propionic acid
(c) succinic acid
(d) malonic acid
Answer: d  

Question: The most reactive compound towards formation of cyanohydrin on treatment with HCN followed by acidification is
(a) benzaldehyde
(b) p -nitrobenzaldehyde
(c) phenylacetaldehyde
(d) p-hydroxybenzaldehyde
Answer: b

Question: A compound, containing only carbon, hydrogen and oxygen, has a molecular weight of 44. On complete oxidation, it is converted into a compound of molecular weight 60. The original compound is 
(a) an aldehyde
(b) an acid
(c) an alcohol
(d) an ether
Answer: a 

Question: What is the oxidation number of carbonyl carbon in acetophenone? 
(a) + 3
(b) + 1
(c) + 2
(d) Zero 
Answer: c

Question: Which of the following reactions can be used to change benzaldehyde to cinnarnic acid?
(a) Perkin's reaction 
(b) Knoevenagel reaction
(c) Reformatsky reaction and ketones
(d) Benzoin condensation
Answer: a

Question: An organic compound Xis oxidised by using acidified K₂Cr₂O₇ . The product obtained reacts with phenyl hydrazine but does not answer silver mirror test. The possible structure of X is 
(a) CH₃CH₂OH
(b) CH3—C—CH₃
ll
O
(c) (CH₃ )₂ CHOR
(d) CH₃CHO
Answer: c

Question: CH₃COOH →^LialH₄ X →_300°C^Cu y →_NaOH^Dilute Z In the above reaction, Z is
(a) butanol
(b) aldol
(c) ketol
(d) acetal
Answer: b 

Question: Acetone and acetaldehyde can be distinguished by
(a) Molisch test
(b) Tollen's test 
(c) Schiffs test
(d) lodoform test
Answer: b

Question: Benzaldehyde reacts with ammonia to form 
(a) benzaldehyde ammonia
(b) urotropine
(c) hydrobenzamide
(d) ammonium chloride
Answer: c

Question: Which product is obtained on reduction of methanal in the presence of concentrated NaOH?
(a) Formic acid and methyl alcohol
(b) CO + H₂
(c) Methyl alcohol
(d) Formic acid
Answer: a 

Question: The end products in benzaldehyde are
(a) PhCO₂H,PhCH₂OH
(b) PhCO₂H,PhCH₂CO₂H
(c) PhCH₂OH, PhCOCH₃
(d) PhCO₂H,PhCOCH₃
Answer: a 

Question: C₆H₅CHO→^NH₃? 
(a) (C₆H₅CHN)₂ CH·C₆H₅
(b) C₆H₅NHCH₃
(c) C₆H₅CH₂NH₂
(d) C₆H₅NHC₆H₅
Answer: a 

Question: What represents the best method for producing salicylic acid?
(a) Benzoic acid, strong base, high temperature
(b) Toluene, strong base, water, high temperature
(c) Phenol, base carbondioxide then acid
(d) Bromobenzene, carbonic acid, high temperature 
Answer: c

Question: Which reaction is suitable for the preparation of α-chloroacetic acid?
(a) Hell-Volhard-Zelinsky reaction
(b) Nefreaction
(c) Stephen's reaction
(d) Perkin condensation
Answer: a

Question: The end product 'C' in the following sequence of chemical reactions is
 CH₃COOH →^CaCO₃ A →^HeatB →^NH₂OH C 
(a) acetaldehyde oxime
(b) formaldehyde oxime
(c) methyl nitrate
(d) acetoxime
Answer: d 

Question: How will you convert butan-2-one to propanoic acid?
(a) Tollen's reagent 
(b) Fehling's solution
(c) NaOH/I₂/H⁺
(d) NaOH/ NaI/ H⁺
Answer: c 

Question: Main product obtained from the reaction of ammonia and formaldehyde is 
(a) formic acid
(b) methylamine
(c) methanol
(d) urotropine
Answer: d

Question: Acetone reacts with Grignard reagent to form 
(a) 3° alcohol
(b) 2° alcohol
(c) ether
(d) No reaction
Answer: a 

Question: Self condensation of acetaldehyde in the presence of dilute alkalies gives
(a) an acetal
(b) an aldol
(c) mesitylene
(d) propionaldehyde
Answer: b 

Question: CH₃COCH₃ and CH₃CH₂CHO can be distinguished by
(a) FeCl₃
(b) Tollen's reagent 
(c) NaHSO₃
(d) 2, 4-DNP
Answer: b 

Question: In a reaction RCHO is reduced to RCH₃ using amalgamated zinc and concentrated HCl and wanning the solution. The reaction is known as 
(a) Meerwein-Ponndorf reaction
(b) Clemmensen's reduction
(c) Wolff-Kishner reduction
(d) Schiff's reaction
Answer: b  

Question: The reaction of CO₂ with sodium phenoxide at 400 K result in
(a) benzoic acid
(b) sodium benzoate
(c) salicylaldehyde
(d) sodium salicylate
Answer: d 

Question: Which one of the following is reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon?
(a) Ethyl acetate 
(b) Acetic acid
(c) Acetamide
(d) Butan-2-one 
Answer: d 

Question: The product formed when hydroxylamine condenses with a carbonyl compound is called 
(a) hydrazide
(b) oxime
(c) hydrazine
(d) hydrazone
Answer: b  

Question: Which of the following compounds would be the main product of an aldol condensation of acetaldehyde and acetone? 
(a) CH₃CH = CH·CHO
(b) CH₃CH = CHCOCH₃
(c) (CH₃)₂C = CH·CHO
(d) (CH₃)₂C = CHCOCH₃
Answer: b

Question: In which of the below reaction do we find α,β-unsaturated carbonyl compounds undergoing a ring closure reaction with conjugated dienes? 
(a) Perkin reaction
(b) Diels-Alder reaction
(c) Claisen rearrangement
(d) Hofmann reaction
Answer: b

Question: Compound (A )(molecular formula C₃H₈O) is treated with acidified potassium dichromate to form a product B (molecular formula C₃H₆O). 'B' forms a shining silver m.itTor on wanning with ammoniacal silver nitrate. 'B' when treated with an aqueous solution of H₂NCONHNH₂ · HCl and sodium acetate gives a product' C'. Identify the structure of 'C'.
(a) CH₃CH₂CH = NNHCONH₂
(b) (CH₃)₂C=NNHCONH₂
(c) (CH₃)₂C = NCONHNH₂
(d) CH₃CH₂CH=NCONHNH₂
Answer: d 

Question: When acetaldehyde is heated with Fehling's solution, a red precipitate is formed. Which of the following is that?
(a) Cu₂O
(b) Cu 
(c) CuO
(d) CuSO₄
Answer: a

Question: CH₃—CHO+ HCN→ A
Compound A on hydrolysis gives
(a) CH₃ — CH₂ — COOH
(b) CH₃ — CH₂ — CH₂ — NH₂
(c) CH₃ — CO — COOH
(d) CH₃ — CO — CH=NOH
(e) CH₃ — CH — COOH
                 l
               OH

Answer: e 

Question: Which of the following organic compounds answers to both iodoform test and Fehling's test? 
(a) Ethanol
(b) Methanal
(c) Ethanal
(d) Propanone
Answer: c

Question: On reaction with hydroxylamine, aldehydes produce
(a) ketoxime
(b) hydrazone 
(c) semicarbazone
(d) aldoxime
Answer: d

Question: Which of the following does not undergo Cannizz.aro's reaction? 
(a) Benzaldebyde
(b) 2-methylpropanal
(c) p-methoxybenzaldebyde
(d) 2, 2-dimethylpropanal
(e) Formaldehyde
Answer: d 

Question: Benzaldehyde and acetone can be best distinguished using
(a) Fehling's solution 
(b) sodium hydroxide solution
(c) 2, 4-DNP
(d) Tollen's reagent
Answer: d

Question: Aldehyde with NH₂ · NH₂ forms 
(a) hydrazones
(b) aniline
(c) nitrobenzene
(d) None of the above
Answer: a 

Question: Benedict's solution is not reduced by
(a) formaldehyde
(b) acetaldehyde
(c) glucose
(d) acetic anhydride
Answer: d 

Question: Acetone on addition to methyl magnesiwn bromide forms a complex, which on decomposition with acid gives X and Mg(OH)Br. Which one of the following is X?
(a) CH₃ OH 
(b) (CH₃)₃ COH
(c) (CH₃)₂ CHOH
(d) CH₃CH₂OH
Answer: b

Question: Acetals are
(a) ketones
(b) di ethers
(c) aldehyde
(d) hydroxy aldehydes
Answer: b  

Question: Benzaldehyde reacts with methyl amine to give
(a) C₆H₅NH₂
(b) C₆H₅CH₂ NI-I₂
(c) C₆H₅CH=NCH₃
(d) C₆H₅CONH₂
Answer: c 

Question: Aldehydes can be oxidised by 
(a) Tollen's reagent
(b) Fehling's solution
(c) Benedict solution
(d) All of these 
Answer: d 

Question: Cyanohydrin of which of the following forms lactic acid?
(a) HCHO
(b) CH₃COCH₃
(c) CH₃CHO
(d) CH₃CH₂CHO
Answer: c 

Question: Identify the reaction which is used to obtain β- hydroxy ketone. 
(a) Condensation reaction
(b) Aldo! condensation
(c) Cross aldol condensation
(d) Cannizzaro reaction
Answer: b 

Question: Which factor/s will increase the reactivity of ›C = O group? 
I. Presence ofa group with positive inductive effect.
II. Presence of a group with negative inductive effect.
III. Presence of large alkyl group.
(a) Only I
(b) Only II
(c) I and III
(d) II and III
Answer: b 

Question: Q11T2
Identify Z from the following. 
(a) Ethyl acetate
(b) Acetic acid
(c) Propanoic acid
(d) Methyl acetate
Answer: b 

Question: The increasing order of the rate of HCN addition to compounds A - D is
(A) HCHO
(B) CH₃COCH₃
(C) PhCOCH₃
(D) PhCOPh 
(a) A < B < C < D
(b) D < B < C < A
(c) D < C < B < A
(d) C < D < B < A
Answer: c