Aldehydes Ketones And Carboxylic Acids Important Questions contains the most important Multiple Choice Questions for NEET, JEE, AIIMS and other medical exams. It has been designed to improve the concepts of CBSE students so that they can clear these competitive exams. These MCQs have been prepared in a systematic manner. For revising a topic it is a good resource for students.
Aldehydes Ketones And Carboxylic Acids Important Questions
These Aldehydes Ketones And Carboxylic Acids Important Questions are based on the following topics:
Aldehydes Ketones And Carboxylic Acids Important Questions
1. Which carboxylic acid is used in the manufacturing of nylon-6,6?
a) Propanedioic acid
b) Butanedioic acid
c) Pentanedioic acid
d) Hexanedioic acid
Answer: d
2. Esters of which acid are used in the perfume industry?
a) Ethanoic acid
b) Benzoic acid
c) Phthalic acid
d) Formic acid
Answer: b
3. Which of the following is the most acidic?
a) Benzoic acid
b) o-Toluic acid
c) m-Toluic acid
d) p-Toluic acid
Answer: b
4. Which of the following has a higher acidic character than benzoic acid?
a) Acetic acid
b) p-Methoxybenzoic acid
c) p-Bromobenzoic acid
d) p-Aminobenzoic acid
Answer: c
5. The reaction of carboxylic acids with NaHCO3 produces ______ which helps it to differentiate it from phenols.
a) H2O
b) CO
c) CO2
d) NaCl
Answer: c
6. The pKa value is equivalent to ________
a) logKa
b) -logKa
c) logKeq
d) -logKeq
Answer: b
7. If the pKa value of acetic acid is 4.76, predict the pKa value of HCl.
a) -7
b) 4.2
c) 7
d) 10
Answer: a
8. How many molecules of acetic acid react with H2SO4 on heating to give one molecule of acetic anhydride?
a) 1
b) 2
c) 3
d) 4
Answer: b
9. Esterification of carboxylic acids is a/an __________ reaction.
a) irreversible
b) nucleophilic addition
c) electrophilic substitution
d) nucleophilic substitution
Answer: d
10. Benzoic acid reacts with phosphorus pentaoxide in the presence of heat to give ________
a) C6H5OC6H5
b) C6H5COC6H5
c) C6H5COOC6H5
d) C6H5COOCOC6H5
Answer: d
11. Which of the following is the most suitable catalyst for the esterification of acetic acid with ethanol?
a) P2O5
b) HCl gas
c) KMnO4-KOH
d) Pyridine
Answer: b
12. Which of the following is used to shift the esterification reaction of carboxylic acids towards the right?
a) Using excess of carboxylic acid
b) Using excess of acid catalyst
c) Removal of water by distillation
d) Removal of ester by distillation
Answer: c
13. Which of the following carboxylic acids is most reactive towards esterification with given alcohol?
a) HCOOH
b) CH3COOH
c) (CH3)2CHCOOH
d) (CH3)3CCOOH
Answer: a
14. Which is the most preferred reagent in the product of acetyl chloride from acetic acid?
a) Cl2
b) PCl3
c) PCl5
d) SOCl2
Answer: d
15. What is the correct order of boiling points of the following?
a) HCOOH > CH3COOH > C2H5COOH
b) C2H5COOH > CH3COOH > HCOOH
c) HCOOH > C2H5COOH > CH3COOH
d) CH3COOH > HCOOH > C2H5COOH
Answer: b
16. If the boiling point of propanol is 370 K, predict the boiling point of acetic acid.
a) 322 K
b) 329 K
c) 370 K
d) 390 K
Answer: d
17. Which of the following aliphatic carboxylic acids is a solid at room temperature?
a) Heptanoic acid
b) Octanoic acid
c) Nonanoic acid
d) Decanoic acid
Answer: d
18. Which among the following has the most unpleasant odour?
a) Caproic acid
b) Lauric acid
c) Myristic acid
d) Palmitic acid
Answer: a
19. How can methyl magnesium bromide be converted to propanoic acid?
a) Jones reagent
b) KMnO4-KOH; heat
c) H3O+; heat
d) CO2-dry ether; H3o+
Answer: d
20. 3-Chlorophenyl magnesium bromide on reaction with dry ice followed by acidification in mineral acid gives _________
a) 3-Chlorophenol
b) 3-Chlorophenylethanoic acid
c) 3-Chlorobenzaldehyde
d) 3-Chlorobenzoic acid
Answer: d
21. Benzoic ethanoic anhydride on hydrolysis gives __________
a) benzoic acid and methanoic acid
b) benzoic acid and ethanoic acid
c) phenylethanoic acid and methanoic acid
d) no products
Answer: b
22. Ethanoyl chloride on hydrolysis with aqueous NaOH gives _______
a) acetate ion
b) acetic acid
c) propanoic acid
d) no reaction
Answer: a
23. The final product(s) of basic hydrolysis followed by acidification of ethyl butanoate is _______
a) ethanoic acid
b) butanoic acid
c) ethanoic acid and butanoic acid
d) butanoic acid and ethanol
Answer: b
24. What is the IUPAC name of (C6H5)CH2CH2COOH?
a) 2-Phenylethanoic acid
b) 2-Phenylpropanoic acid
c) 3-Phenylethanoic acid
d) 3-Phenylpropanoic acid
Answer: 3-Phenylpropanoic acid
25. What is the IUPAC name of (CH3)3CCH2COOH?
a) Hexanoic acid
b) 2,2,2-Trimethylpropanoic acid
c) 3,3-Dimethylbutanoic acid
d) 4-Methylpentanoic acid
Answer: 3,3-Dimethylbutanoic acid
26. Butyric acid was first obtained from _______
a) red ants
b) vinegar
c) rancid butter
d) goats
Answer: rancid butter
27. What is the common name of the simplest dicarboxylic acid?
a) Oxalic acid
b) Malonic acid
c) Acetic acid
d) Propionic acid
Answer: Oxalic acid
28. Which of the following is not a use of formaldehyde?
a) Preservation of biological specimens
b) Manufacturing of bakelite
c) Silvering of mirrors
d) Preparation of acetic acid.
Answer: d
29. What is the correct order of reactivity towards nucleophilic addition?
a) Benzaldehyde > Benzophenone > Acetophenone
b) Benzophenone > Benzaldehyde > Acetophenone
c) Acetophenone > Benzaldehyde > Benzophenone
d) Benzaldehyde > Acetophenone > Benzophenone
Answer: d
30. Which of the following is the most reactive towards hydrogen cyanide?
a) Acetophenone
b) Benzaldehyde
c) p-Nitrobenzaldehyde
d) p-Tolualdehyde
Answer: c
31. Identify the catalyst in the nucleophilic addition of HCN to acetone.
a) NaOH
b) HCl
c) NaCl
d) NaCN
Answer: a
32. The hydrolysis of the addition product of acetone and methyl magnesium iodide gives _______
a) ethyl alcohol
b) isopropyl alcohol
c) tert-Butyl alcohol
d) phenol
Answer: c
33. Acetone reacts with ethylene glycol in dry HCl gas to form _________
a) hemiacetals
b) acetals
c) cyclic acetals
d) cyclic ketals
Answer: d
34. Which of the following products is formed when an aldehyde reacts with an amine in acidic medium?
a) Imine
b) Schiff’s base
c) Oxime
d) Hydrazone
Answer: b
35. Identify the N-substituted derivative of carbonyl compounds that are coloured compounds and are useful in the identification of aldehydes and ketones.
a) Hydrazone
b) Phenylhydrazone
c) 2,4-Dinitrophenylhydrazone
d) Semicarbazone
Answer: c
36. Aldehydes and ketones undergo __________ reactions.
a) electrophilic addition
b) electrophilic substitution
c) nucleophilic addition
d) nucleophilic substitution
Answer: c
37. Which of the following is added to the tetrahedral intermediate when it reacts with a proton from the reaction medium?
a) Nu–
b) H+
c) Both Nu– and H+
d) OH–
Answer: b
38. The nucleophilic addition reactions of aldehydes are carried out in ________ medium.
a) neutral
b) acidic
c) weakly basic
d) extremely basic
Answer: b
39. Catalytic hydrogenation of _______ gives propan-2-ol.
a) formaldehyde
b) acetaldehyde
c) propionaldehyde
d) acetone
Answer: d
40. What is the product of Clemmensen reduction on acetophenone?
a) Benzaldehyde
b) Methyl benzene
c) Ethyl benzene
d) Benzophenone
Answer: c
41. A compound on treatment with hydrazine followed by heating up to 473K with KOH in ethylene glycol gives propane. Identify the compound.
a) Methanal
b) Ethanal
c) Propanal
d) Acetone
Answer: d
42. Acetaldehyde is oxidised to ______ in the presence of nitric acid.
a) methanoic acid
b) ethanoic acid
c) acetone
d) ethanol
Answer: b
43. What are the major products of the oxidation of pentan-2-one with concentrated HNO3 at very high temperatures?
a) Butanoic acid and methanoic acid
b) Propanoic acid and ethanoic acid
c) Pentanoic acid
d) Butanoic acid and ethanoic acid
Answer: b
44. Which of the following compounds helps in reducing esters to aldehydes?
a) BINAL-H
b) DIBAL-H
c) DIPT
d) TBAF
Answer: DIBAL-H
45. Identify the reagent(s) for the conversion of chlorobenzene to 3-chlorobenzaldehyde.
a) CrO3 and (CH3CO)2O
b) CrO2Cl2; H2O
c) Cl2/hv; H2O
d) CO, HCl and CuCl
Answer: CO, HCl and CuCl
46. Acetyl chloride reacts with _______ to give butan-2-one.
a) cadmium chloride
b) methyl magnesium chloride
c) dimethyl cadmium
d) diethyl cadmium
Answer: diethyl cadmium
47. What is formed after the hydrolysis of the product of the reaction between benzonitrile and methyl magnesium bromide in dry ether?
a) Phenyl acetaldehyde
b) Acetophenone
c) 1-Phenylpropanone
d) Benzaldehyde
Answer: Acetophenone
48. What is the common name of butanal?
a) n-Butanaldehyde
b) α-Butanaldehyde
c) n-Butyraldehyde
d) α-Butyraldehyde
Answer: n-Butyraldehyde
49. Acetone is the common name of which of the following ketones?
a) Dimethyl ketone
b) Ethyl methyl ketone
c) Diethyl ketone
d) Methyl n-propyl ketone
Answer: Dimethyl ketone
50. Which of the following will be the main group when present in a compound together?
a) -CHO
b) -CO
c) -OH
d) -Cl
Answer: -CHO
FAQs on Aldehydes, Ketones and Carboxylic acids
Why carboxylic acids do not show typical reactions of aldehydes and ketones?
Carboxylic acids do not give characteristic reaction of carbonyl group because the presence of lone pairs on oxygen atom attached to hydrogen atom in the -COOH group are involved in resonance thereby making the carbon atom less electrophilic. This also reflects that carboxylic acids are not good nucleophiles.
How can we easily differentiate between carboxylic acids and ketones and aldehydes?
The Tollens’ test is a reaction that is used to distinguish aldehydes from ketones, as aldehydes are able to be oxidized into a carboxylic acid while ketones cannot. The Tollens’ reagent, which is a mixture of silver nitrate and ammonia, oxidizes the aldehyde to a carboxylic acid.