CBSE Class 12 Chemistry Aldehydes Ketones Notes

Question. In the presence of a dilute base 6 5 C H CHO and 3 CH CHO react together to give a product. The product is:
a. C₆ H₅ CH₃
b. C₆ H₅ CH₂ CH₂ OH
c. C₆ H₅ CH₂ OH
d. C₆ H₅ CH = CHCHO
Answer : D

Question. From which of the following tertiary butyl alcohol is obtained by the action of methyl magnesium iodide?
a. HCHO
b. CH₃ CHO
c. CH₃ COCH₃
d. CO₂
Answer : C

Question. Which of the following compound gives a ketone with Grignard reagent?
a. Formaldehyde
b. Ethyl alcohol
c. Methyl cyanide
d. Methyl iodide
Answer : C

Question. The oxidation of benzyl chloride with lead nitrate gives:
a. Benzyl alcohol
b. Benzoic acid
c. Benzaldehyde
d. p-chlorobenzaldehyde
Answer : B

Question. During reaction of benzaldehyde with alkali one of the product is:
a. Phenol
b. Benzyl alcohol
c. Benzene
d. Benzophenone
Answer : B

Question. The reaction
C₆H₅CHO + CH₃ CHO → C₆H₅CH == CH—CHO is known as:
a. Perkin's reaction
b. Claisen condensation
c. Benzoin condensation
d. Cannizzaro's reaction
Answer : B

Question. Dry heating of calcium acetate gives:
a. Acetaldehyde
b. Ethane
c. Acetic acid
d. Acetone
Answer : D

Question. Methyl ethyl ketone is prepared by the oxidation of: 
a. 2-propanol
b. 1-butanol
c. 2-butanol
d. t-butyl alcohol
Answer : D

Question. IUPAC name of CCl₃ CHO is:
a. Chloral
b. Trichloro acetaldehyde
c. 1, 1, 1-trichloroethanal
d. 2, 2, 2-trichloroethanal
Answer : D

Question. Which one of the following pairs is not correctly matched?

Answer : B

Question. Which of the following gives aldol condensation reaction?

Answer : C

Question. Which of the following organic compounds exhibits positive Fehling test as well as iodoform test?
a. Methanal
b. Ethanol
c. Propanone
d. Ethanal
Answer : D

Question. Ethyne on reaction with water in the presence of 4 HgSO and 2 4 H SO gives:
a. Acetone
b. Acetaldehyde
c. Acetic acid
d. Ethyl alcohol
Answer : B

Question. Consider the following statement Acetophenone can be prepared by:
(A) Oxidation of 1-phenylethanol
(B) Reaction of benzalthanol with methyl magnesium bromide
(C) Friedel craft’s reaction of benzene with acetyl chloride
(D) Distillation of calcium benzoate
a. A and B
b. A and D
c. A and C
d. C and D
Answer : C

Question. On heating calcium acetate and calcium formate, the product formed is:
a. CH₃ COCH₃
b. CH₃ CHO
c. HCHO+ CaCO₃
d. CH₃ CHO+ CaCO₃
Answer : D

Question. Benzaldehyde and acetaldehyde can be differentiated by:
a. HCN
b. NH₂ OH
c. Hydrazine
d. NaOH solution
Answer : D

Question. The end product in the following sequence of reaction is:

a. Acetic acid
b. Isopropyl alcohol
c. Acetone
d. Ethanol
Answer : C

Question. Compound which gives acetone on ozonolysis?
a. CH₃ −CH = CH−CH₃
b. (CH₃)₂ C = C(CH₃)₂
c. C₆ H₅ CH = CH₂
d. CH₃ CH = CH₂
Answer : B

Question. Aldol condensation will not be observed in :
a. Chloral
b. Phenyl acetaldehyde
c. Hexanal
d. Ethanol
Answer : A

Question. Which of the following compounds containing carbonyl group will give coloured crystalline compound with?

a. CH₃ COCl
b. CH₃ COCH₃
c. CH₃ CO(OC₂ H₅)
d. CH₃ CONH₂
Answer : B

Question. The compound obtained by the reduction of propionaldehyde by amalgamated zinc and concentrated HCl is:
a. Propanol
b. Propane
c. Propene
d. All of these
Answer : B

Question. Formaldehyde when treated with KOH gives methanol and potassium formate. The reaction is known as?
a. Perkin reaction
b. Claisen reaction
c. Cannizzaro reaction
d. Knoevenagel reaction
Answer : C

Question. Which of the following does not give brick red precipitate with Fehling solution?
a. Acetone
b. Acetaldehyde
c. Formalin
d. D-glucose
Answer : A

Question. Acetaldehyde when treated with dilute NaOH gives?

Answer : C

Question. C₂H₅CHO and (CH₃)₂ CO can be distinguished by testing with:
a. Phenyl hydrazine
b. Hydroxylamine
c. Fehling solution
d. Sodium bisulphite
Answer : C

Question. Which of the following products is formed when benzaldehyde is treated with 3 CH MgBr and the addition product so obtained is subjected to acid hydrolysis?
a. Secondary alcohol
b. A primary alcohol
c. Phenol
d. Tert-Butyl alcohol
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. To distinguish between formaldehyde and acetaldehyde, we require:
a. Tollen's reagent
b. Fehling's solution
c. Schiff's reagent
d. Caustic soda solution
Answer : D

Question. Dimethyl ketones are usually characterised through:
a. Tollen's reagent
b. Iodoform test
c. Schiff's test
d. Benedict's reagent
Answer : B

Question. If formaldehyde and KOH are heated, then we get:
a. Acetylene
b. Methane
c. Methyl alcohol
d. Ethyl formate
Answer : C

Question. The alkaline CuSO₄ containing sodium potassium tart rate does not react with:
a. CH₃ CHO
b. C₂ H₅ CHO
c. C₆ H₅ CH₂ CHO
d. C₆ H₅ CHO
Answer : D

Question. The light yellow compound produced when acetone reacts with iodine and alkali, is?
a. CH₃.CO.CH₂ I
b. CH₃I
c. CHI₃
d. None of these
Answer : C

Question. Which of the following will undergo aldol condensation?
a. Acetaldehyde
b. Propanaldehyde
c. Benzaldehyde
d. Trideuteroacetaldehyde
Answer : A. B. D

Question. Acetaldehyde cannot show:
a. Iodoform test
b. Lucas test
c. Benedict's test
d. Tollen's test
Answer : B

Question. Correct order of reactivity of CH₃ CHO,C₂ H₆ COCH₃ and CH₃ COCH₃ is:
a. CH₃ CHO > CH₃ COCH₃ > CH₃ COC₂ H₅
b. C₂ H₅ COCH₃ > CH₃ COCH₃ > CH₃ CHO
c. CH₃ COCH₃ > CH₃ CHO > C₂ H₅ COCH₃
d. CH₃ COCH₃ > C₂ H₅ COCH₃ > CH₃ CHO
Answer : A

Question. One mole of an organic compound requires 0.5 mole of oxygen to produce an acid. The compound may be:
a. Alcohol
b. Ether
c. Ketone
d. Aldehyde
Answer : D

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

Question. Acetaldehyde and acetone differ in their reaction with:
a. Sodium bisulphite
b. Ammonia
c. Phosphorus pentachloride
d. Phenyl hydrazine
Answer : B

Question. CH₃ CHO react with aqueous NaOH solution to form:
a. 3-hydroxy butanal
b. 2-hydroxy butanal
c. 4-hydroxy butanal
d. 3-hydroxy butanol
Answer : A

Question. Identify the product Y in the sequence:

a. CH₃ OH
b. CH₃ CH₂ OH
c. (CH₃)₂ CHOH
d. (CH₃)₃ COH
Answer : C

Question. Which of the following reagents is used to distinguish acetone and acetophenone?
a. NaHSO₃
b. Grignard reagent
c. Na₂ SO₄
d. NH₄ Cl
Answer : A

Question. Cinnamic acid is formed when 6 5 C H −CHO condenses with 3 2 (CH CO) O in presence of?
a. Conc. H₂ SO₄
b. Sodium acetate
c. Sodium metal
d. Anhydrous ZnCl₂
Answer : B

Question. A mixture of benzaldehyde and formaldehyde on heating with aqueous NaOH solution gives:
a. Benzyl alcohol and sodium formate
b. Sodium benzoate and methyl alcohol
c. Sodium benzoate and sodium formate
d. Benzyl alcohol and methyl alcohol
Answer : A

Question. Aldehydes and ketones can be reduced to hydrocarbon by using:
a. LiAlH₄
b. H₂ / Pd − BaSO₄
c. Na −Hg /HCl
d. NH₂ − NH₂ / C₂ H₅ ONa
Answer : D

Question. Which gives difference between aldehyde and ketone?
a. Fehling's solution
b. Tollen's reagent
c. Schiff's reagent
d. Benedict's solution
e. All of these
Answer : C

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