Chemistry 2nd Year Aldehydes and Ketones MCQs

You can get the Chemistry 2nd Year Aldehydes and Ketones MCQs with answers here. Aldehydes and Ketones are the organic compounds containing the carbonyl group. Both have different nomenclature. Aldehydes are manufactured in laboratories and Industries. There are various reactions to carbonyl compounds. The nucleophilic addition reactions take place in carbonyl compounds. The first one is Base-Catalysed Addition Reaction which includes Condensation reactions, Cannizzaro’s reaction, Haloform reaction. The second one is the Acid-Catalysed Addition reaction includes the Reaction of Addition of Alcohols and Ammonia Derivatives. Oxidation and Reduction Reactions are also very important to take place in Aldehydes and Ketones. Carbonyl compounds are identified using different tests. Aldehydes are used in the manufacture of different products. This chapter has a lot of importance with the entry test point of view. So, have a look at the important MCQs of this chapter.

Chemistry 2nd Year Aldehydes and Ketones MCQs

KEY POINTS

 

Question#1: Symmetrical structure of a ketone refers to:

• The uneven number of carbon atoms on either side of the carbonyl group
• The same number of carbon atoms on either side of the carbonyl group
• Just I carbon more on the right of the carbonyl group
• Just I carbon more on the left of the carbonyl group

Question#2: Which of the following can be used for the oxidative preparation of aldehydes from alcohol?

• Pt-asbestos
• FeO and MO₂O₃
• Na₂Cr₂O₇and h₂SO₄
• All of these

Question#3: Ethylene is oxidized to acetaldehyde on a commercial scale by the use of the catalyst which is:

• PdCI₂ and CuCI₂
• FeO and Mo₂O₃
• Na₂Cr₂O₇ and H₂SO₄
• All of these

Question#4: The clear fact for the structural differences between aldehyde and ketone is:

• A ketone has one R group attached on the carbonyl group
• An aldehyde has two R groups attached on the carbonyl group
• An aldehyde has one R and a ketone has two R group attached to a carbonyl group
• Both A and C

Question#5: Formation of yellow or orange /red precipitates with 2,4-DNPH refers to the identification of:

• Aldehydes
• Both A and C
• Ketones
• Pure alcohols only

Question#6: An alcohol giving positive 2,4-DNPH test implies that:

• It is 100% pure
• It may contain some contents of aldehydes and ketones
• It is ethanol
• None of these

Question#7: Reduction of an aldehyde using NaBH₄gives:

• Primary alcohol
• Tertiary alcohol
• Secondary alcohol
• Phenol

Question#8: Reduction of a ketone using NaBH₄ gives:

• Primary alcohol
• Tertiary alcohol
• Secondary alcohol
• Phenol

Question#9: HCN can be added to:

• Aldehydes
• Ketones
• Ethers
• Both A and C

Question#10: Addition of HCN to acetaldehyde in the presence of dilute mineral acid and sodium cyanide forms:

• Formaldehyde cyanohydrins
• Acetone cyanohydrins
• Acetaldehyde cyanohydrin
• Butanone cyanohydrins

Question#11: Acidified hydrolysis of cyanohydrins form.

• Carboxylic acids
• Hydroxyl-carboxylic acids
• Alcohols
• Aldols and ketols

Question#12: Haloform test is given by:

• Acetaldehyde
• Propanone
• Melty group ketones
• All of these

Question#13: CHX₃ will be given by all the carbonyl compounds containing at least one:

• EthyI group
• IsopropyI group
• methyl group
• Both B and C are correct

Question#14: In the oxidation of unsymmetrical ketones using strong oxidizing agents like conc.HNO₃, which carbon atom is preferentially attacked:

• A carbon atom with the maximum number of hydrogen atoms
• A carbon atom with the least number of hydrogen atoms
• Alpha
• Beta carbon

Question#15: Which of the following ketones will produce acid only after oxidation by acidified potassium dichromate?

• EthyI n-propyI ketone
• ethyl methyl ketone
• dimethyl ketone
• diethyl ketone

Question#16: What will be the product in the following reaction?

CH₃ CH=CHCH₂  COCH₃ ———?

• CH₃CH₂ CH₂ CH₂COCH₃
• CH₃ CH₂ CH₂ CH₂CH(OH) CH₃
• CH₃ CH= CHCH₂ CH(OH) CH₃
• All of these

Question#17: Which of the following will not form enolate ion?

• CH₃COCH₃
• CH₃SwHO
• HCHO
• All of these

Question#18: In this compound C1H₂-C₂CH₃ the hybridization of carbon number 1 and carbon number 2.

• Sp³ ,Sp³
• Sp^{2 ,}Sp²
• Sp^2, Sp³
• ^Sp, Sp²

Question#19: Which of the following has maximum steric hindrance?

• (C₂H₅)₂CO
• CH₃COCH₃
• C₃H₇COCH₃
• CH₃COH

Question#20: Which of the following has maximum reactivity in nucleophilic substitution reactions?

• Formaldehyde
• Acetaldehyde
• Propanone
• All of these

Question#21: Formation of cyanohydrins form an aldehyde is an example of:

• Nucleophilic substitution
• Nucleophilic addition
• Electrophilic addition
• Electrophilic substitution

Question#22: For which one of the following pairs of compounds can the members be distinguished by means of Tollen’s test.

• HCHO and CH₃ CHO
• CH₃CHO and CH₃COCH₃
• HCHO
• CH₃ CH₂ CH(CHO) CH₃

Question#23: All of the following react with Fehling solution except:

• CH₃ CH₂ Cho
• CH₃ CH₂COCH₃
• HCHO
• CH₃ CH₂ CH(CHO) CH₃

Question#24:Which of the following will not give an iodoform test?

• Ethanol
• Ethanol
• 3-pentanone
• 2-pentanone

Question#25: Which substance does not oxidize easily?

• CH₃ CH₂CHO
• CH₃ CHO
• HCHO
• CH₃COCH₃

Question#26: Which one of the following sets of compounds oxidizes aldehydes as well as ketones?

• CuSO₄+NaOH+Citric acid
• CuSO₄+ NaOH+Tartaric acid
• AgNO₃+NH₄OH
• K₂Cr₂O₇+Cone.H₂SO₄

Question#27:Acetaldehyde reacts normally with:

• Electrophiles only
• Nucleophiles only
• Electrophiles and nucleophiles
• Free radicals only

Question#28: The structural formula of the compound which is an isomer of acetone is:

• CH₃ CH₂ CHO
• CH₃ CH₂ CH₂CHO
• CH₃ CH₂OH
• CH₃ CH₂ CH₂OH

Question#29:2-Pentanone and 3-pentanone are:

• Metamers
• Functional group isomers
• Geometrical isomers
• Chain isomers

Question#30: Ethylene is oxidized to acetaldehyde on a commercial scale by the use of the catalyst which is:

• PdCI₂ and CuCI₂
• FeO and Mo₂O₃
• Na₂Cr₂O₇ and H₂SO₄
• All of these