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

Question.Which one of the following can be oxidised to the corresponding carbonyl compound?
(a) 2-Hydroxypropan
(b) ortho-Nitrophenol
(c) Phenol
(d) 2-Methyl-2-hydroxypropane

Answer : A

Question. In the reaction, CH₃CN + 2H → ^HCl Ether → X→ ^{Boiling H2OY}; the term Y is
(a) acetaldehyde
(b) ethanamine
(c) acetone
(d) dimethylamine.

Answer : A

Question. Ketones [RCOR₁] where R = R₁ = alkyl group. It can be obtained in one step by
(a) oxidation of tertiary alcohol
(b) reaction of acid halide with alcohols
(c) hydrolysis of esters
(d) oxidation of primary alcohol.

Answer : A

Question. The oxidation of toluene to benzaldehyde by chromyl chloride is called
(a) Etard reaction
(b) Riemer–Tiemann reaction
(c) Wurtz reaction
(d) Cannizzaro’s reaction.

Answer : A

Question. Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as
(a) Aldol condensation
(b) Cannizzaro’s reaction
(c) Cross Cannizzaro’s reaction
(d) Cross Aldol condensation.

Answer : D

Question. Sodium phenoxide when heated with CO2 under pressure at 125°C yields a product which on acetylation producesC.

Answer : A

Question. The compound that undergoes decarboxyliation most readily under mild condition is

Answer : A

Question. Which of the product is formed when acetone is reacted with barium hydroxide solution?

Answer : A

Question. Identify Din the following reaction

(a) HOOC—CH₂—COOH
(b) OHC—CH₂—COOH
(c) OHC—CH₂—CHO
(d) HO—CH=CH—COOH

Answer : B

Question. Which one of the following is an Hell-Volhard-Zelinsky reaction?

Answer : B

Question. Compound A has a molecular formula C2Cl3OH. It reduces Fehling’s solution and on oxidation, it gives a monocarboxylic acid B. If A is obtained by the action of chlorine on ethyl lcohol, then compound A is
(a) methyl chloride
(b) monochloroacetic acid
(c) chloral
(d) chloroform.

Answer : C

Question. Which of the following compounds will undergo self aldol condensation in the presence of cold dilute alkali?
(a) CH C — CHO
(b) CH₂ CHCHO
(c) C₆H₅CHO
(d) CH₃CH₂CHO

Answer : D

Question. Which of the following compounds will give positive test with Tollens’ reagent?
(a) Acetic acid
(b) Acetone
(c) Acetamide
(d) Acetaldehyde

Answer : D

 Question. (CH₃)₂C= CHCOCH₃ can be oxidised to (CH₃)₂C=CHCOOH by
(a) chromic acid
(b) NaOI
(c) Cu at 300°C
(d) KMnO₄

Answer : B

Question. In which of the following, the number of carbon atoms does not remain same when carboxylic acid is obtained by oxidation?
(a) CH₃COCH₃
(b) CCl₃CH₂CHO
(c) CH₃CH₂CH₂OH
(d) CH₃CH₂CHO

Answer : A

Question. Which of the following reagents would distinguish cis-cyclopenta-1,2-diol from the trans-isomer?
(a) MnO₂
(b) Aluminium isopropoxide
(c) Acetone
(d) Ozone

Answer : C

Question. The correct statement regarding a carbonyl compound with a hydrogen atom on its alphacarbon, is
(a) a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as carbonylation
(b) a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as keto-enol tautomerism
(c) a carbonyl compound with a hydrogen atom on its alpha-carbon never equilibrates with its corresponding enol
(d) a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as aldehyde-ketone equilibration

Answer : B

Question. The product formed by the reaction of an aldehyde with a primary amine is
(a) carboxylic acid
(b) aromatic acid
(c) Schiff ’s base
(d) ketone.

Answer : C

Question. Reaction of a carbonyl compound with one of the following reagents involves nucleophilic addition followed by elimination of water. The reagent is
(a) hydrazine in presence of feebly acidic solution
(b) hydrocyanic acid
(c) sodium hydrogen sulphite
(d) a Grignard reagent.

Answer : A

Question. CH₃CHO and C₆H₅CH₂CHO can be distinguished chemically by
(a) Benedict’s test
(b) iodoform test
(c) Tollens’ reagent test
(d) Fehling’s solution test.

Answer : B

Question. Identify the method by which Me₃CCO₂H can be prepared. 
(a) Treating 1 mole of MeCO Me with 2 moles of MeMgI
(b) Treating 1 mole of MeCO₂ Me with 3 moles of MeMgI
(c) Treating 1 mole of MeCHO with 3 moles of MeMgI
(d) Treating 1 mole of dry ice with 1 mole of Me₃CMgI

Answer : D

Question. Benzaldehyde on refluxing with aqueous alcoholic KCN produce
(a) cyanobenzene
(b) cyanohydrin
(c) benzoyl cyanide
(d) benzoin

Answer : D

Question. The strongest acid amongst the following compounds is
(a) CH₃COOH
(b) HCOOH 
(c) CH₃CH₂CH(Cl)CO₂H
(d) ClCH₂CH₂CH₂COOH 

Answer : C

Question. A carbonyl compound reacts with hydrogen cyanide to form cyanohydrin which on hydrolysis forms a racemic mixture of a-hydroxy acid. The carbonyl compound is
(a) formaldehyde
(b) acetaldehyde
(c) acetone
(d) diethyl ketone.

Answer : B

Question. In this reaction : CH₃CHO + HCN → CH₃CH(OH)CN →^HOH CH₃CH(OH)COOH an asymmetric centre is generated. The acid obtained would be
(a) D-isome
(b) L-isomer
(c) 50% D + 50% L-isomer
(d) 20% D + 80% L-isomer.

Answer : C

Question. First product of the reaction between RCHO and NH₂NH₂ is
(a) RCH NNH₂
(b) RCH NH
(c) RCH₂NH₂
(d) RCON₃ 

Answer : A

Question. An ester (A) with molecular formula, C₉H₁₀O₂ was treated with excess of CH₃MgBr and the complex so formed, was treated with H₂SO₄ to give an olefin (B). Ozonolysis of (B) ave a ketone with molecular formula C₈H₈O which shows +ve iodoform test. The structure of (A) is
(a) H₃CCH₂COC₆H₅
(b) C₂H₅COOC₆H₅
(c) C₆H₅COOC₂H₅
(d) p-H₃CO – C₆H₄ – COCH₃

Answer : C

Question. Iodoform test is not given by
(a) ethanal
(b) ethanol
(c) 2-pentanone
(d) 3-pentanone.

Answer : D

Question. The oxidation of toluene with CrO₃ in the presence of (CH₃CO)₂O gives a product A, which on treatment with aqueous NaOH produces
(a) C₆H₅COONa
(b) 2, 4-diacetyl toluene
(c) C₆H₅CHO
(d) (C₆H₅CO)₂O

Answer : A

Question. When aniline reacts with oil of bitter almonds (C6H5CHO) condensation takes place and benzal derivative is formed. This is known as
(a) Schiff ’s base
(b) Benedict’s reagent
(c) Millon’s base
(d) Schiff ’s reagent.

Answer : A

Question. Vinegar is dilute aqueous solution of
(a) ethanoic acid
(b) benzoic acid
(c) citric acid
(d) oxalic acid

Answer : A

Question. Which one of the following acid does not have a carboxylic group?
(a) Methanoic acid
(b) Ethanoic acid
(c) Propanoic acid
(d) Picric acid

Answer : D

Question. An organic compound A on treatment with NH3 gives B, which on heating gives C. C when treated with Br2 in the presence of KOH produces ethyl amine. Compound A is

Answer : D

Question. Which of the following represents the correct order of the acidity in the given compounds?
(a) FCH₂COOH > CH₃COOH > BrCH₂COOH > ClCH₂COOH
(b) BrCH₂COOH > ClCH₂COOH > FCH₂COOH > CH₃COOH
(c) FCH₂COOH > ClCH₂COOH > BrCH₂COOH > CH₃COOH
(d) CH₃COOH > BrCH₂COOH > ClCH₂COOH > FCH₂COOH

Answer : C