Chapter 12 Aldehydes, Ketones And Carboxylic Acids

Question 1. Addition of water to alkynes occurs in acidic medium and in the presence of $Hg^{2+}$ ions as a catalyst. Which of the following products will be formed on addition of water to but-1-yne under these conditions.

(i)

(ii)

(iii)

(iv)

Question 2. Which of the following compounds is most reactive towards nucleophilic addition reactions?

(i)

(ii)

(iii)

(iv)

Question 3. The correct order of increasing acidic strength is _____________.

(i) Phenol < Ethanol < Chloroacetic acid < Acetic acid

(ii) Ethanol < Phenol < Chloroacetic acid < Acetic acid

(iii) Ethanol < Phenol < Acetic acid < Chloroacetic acid

(iv) Chloroacetic acid < Acetic acid < Phenol < Ethanol

Question 4. Compound can be prepared by the reaction of _____________.

(i) Phenol and benzoic acid in the presence of NaOH

(ii) Phenol and benzoyl chloride in the presence of pyridine

(iii) Phenol and benzoyl chloride in the presence of $ZnCl_2$

(iv) Phenol and benzaldehyde in the presence of palladium

Question 5. The reagent which does not react with both, acetone and benzaldehyde.

(i) Sodium hydrogensulphite

(ii) Phenyl hydrazine

(iii) Fehling’s solution

(iv) Grignard reagent

Question 6. Cannizaro’s reaction is not given by _____________.

(i)

(ii)

(iii) H CHO

(iv) $CH_3CHO$

Question 7. Which product is formed when the compound is treated with concentrated aqueous KOH solution?

(i)

(ii)

(iii)

(iv)

Question 8. Structure of ‘A’ and type of isomerism in the above reaction are respectively.

(i) Prop–1–en–2–ol, metamerism

(ii) Prop-1-en-1-ol, tautomerism

(iii) Prop-2-en-2-ol, geometrical isomerism

(iv) Prop-1-en-2-ol, tautomerism

Question 9. Compounds A and C in the following reaction are __________.

(i) identical

(ii) positional isomers

(iii) functional isomers

(iv) optical isomers

Question 10. Which is the most suitable reagent for the following conversion?

(i) Tollen’s reagent

(ii) Benzoyl peroxide

(iii) $I_2$ and NaOH solution

(iv) Sn and NaOH solution

Question 11. Which of the following compounds will give butanone on oxidation with alkaline $KMnO_4$ solution?

(i) Butan-1-ol

(ii) Butan-2-ol

(iii) Both of these

(iv) None of these

Question 12. In Clemmensen Reduction carbonyl compound is treated with _____________.

(i) Zinc amalgam + HCl

(ii) Sodium amalgam + HCl

(iii) Zinc amalgam + nitric acid

(iv) Sodium amalgam + $HNO_3$

Question 13. Which of the following compounds do not undergo aldol condensation?

(i) $CH_3—CHO$

(ii)

(iii)

(iv)

Question 14. Treatment of compound with NaOH solution yields

(i) Phenol

(ii) Sodium phenoxide

(iii) Sodium benzoate

(iv) Benzophenone

Question 15. Which of the following conversions can be carried out by Clemmensen Reduction?

(i) Benzaldehyde into benzyl alcohol

(ii) Cyclohexanone into cyclohexane

(iii) Benzoyl chloride into benzaldehyde

(iv) Benzophenone into diphenyl methane

Question 16. Through which of the following reactions number of carbon atoms can be increased in the chain?

(i) Grignard reaction

(ii) Cannizaro’s reaction

(iii) Aldol condensation

(iv) HVZ reaction

Question 17. Benzophenone can be obtained by ____________.

(i) Benzoyl chloride + Benzene + $AlCl_3$

(ii) Benzoyl chloride + Diphenyl cadmium

(iii) Benzoyl chloride + Phenyl magnesium chloride

(iv) Benzene + Carbon monoxide + $ZnCl_2$

Question 18. Which of the following is the correct representation for intermediate of nucleophilic addition reaction to the given carbonyl compound (A) :

(i)

(ii)

(iii)

(iv)

Question 19. Why is there a large difference in the boiling points of butanal and butan-1-ol?

Question 20. Write a test to differentiate between pentan-2-one and pentan-3-one.

Question 21. Give the IUPAC names of the following compounds

(i)

(ii)

(iii)

(iv) $CH_3—CH=CH—CHO$

Question 22. Give the structure of the following compounds.

(i) 4-Nitropropiophenone

(ii) 2-Hydroxycyclopentanecarbaldehyde

(iii) Phenyl acetaldehyde

Question 23. Write IUPAC names of the following structures.

(i)

(ii)

(iii)

Question 24. Benzaldehyde can be obtained from benzal chloride. Write reactions for obtaining benzalchloride and then benzaldehyde from it.

Question 25. Name the electrophile produced in the reaction of benzene with benzoyl chloride in the presence of anhydrous $AlCl_3$. Name the reaction also.

Question 26. Oxidation of ketones involves carbon-carbon bond cleavage. Name the products formed on oxidation of 2, 5-dimethylhexan-3-one.

Question 27. Arrange the following in decreasing order of their acidic strength and give reason for your answer.

$CH_3CH_2OH, CH_3COOH, ClCH_2COOH, FCH_2COOH, C_6H_5CH_2COOH$

Question 28. What product will be formed on reaction of propanal with 2-methylpropanal in the presence of NaOH? What products will be formed? Write the name of the reaction also.

Question 29. Compound ‘A’ was prepared by oxidation of compound ‘B’ with alkaline $KMnO_4$. Compound ‘A’ on reduction with lithium aluminium hydride gets converted back to compound ‘B’. When compound ‘A’ is heated with compound B in the presence of $H_2SO_4$ it produces fruity smell of compound C to which family the compounds ‘A’, ‘B’ and ‘C’ belong to?

Question 30. Arrange the following in decreasing order of their acidic strength. Give explanation for the arrangement.

$C_6H_5COOH, FCH_2COOH, NO_2CH_2COOH$

Question 31. Alkenes ($>C=C<$) and carbonyl compounds ($>C=O$), both contain a $\pi$ bond but alkenes show electrophilic addition reactions whereas carbonyl compounds show nucleophilic addition reactions. Explain.

Question 32. Carboxylic acids contain carbonyl group but do not show the nucleophilic addition reaction like aldehydes or ketones. Why?

Question 33. Identify the compounds A, B and C in the following reaction.

Question 34. Why are carboxylic acids more acidic than alcohols or phenols although all of them have hydrogen atom attached to a oxygen atom (—O—H)?

Question 35. Complete the following reaction sequence.

Question 36. Ethylbenzene is generally prepared by acetylation of benzene followed by reduction and not by direct alkylation. Think of a possible reason.

Question 37. Can Gatterman-Koch reaction be considered similar to Friedel Craft’s acylation? Discuss.

Question 38. Match the common names given in Column I with the IUPAC names given in Column II.

Question 39. Match the acids given in Column I with their correct IUPAC names given in Column II.

Question 40. Match the reactions given in Column I with the suitable reagents given in Column II.

Question 41. Match the example given in Column I with the name of the reaction in Column II.

Column I (Example)	Column II (Reaction)
(i)	(a) Friedel Crafts acylation
(ii)	(b) HVZ reaction
(iii)	(c) Aldol condensation
(iv)	(d) Cannizaro’s reaction
(v)	(e) Rosenmund’s reduction
(vi)	(f) Stephen’s reaction

Question 42. Assertion : Formaldehyde is a planar molecule.

Reason : It contains $sp^2$ hybridised carbon atom.

Question 43. Assertion : Compounds containing —CHO group are easily oxidised to corresponding carboxylic acids.

Reason : Carboxylic acids can be reduced to alcohols by treatment with $LiAlH_4$.

Question 44. Assertion : The $\alpha$-hydrogen atom in carbonyl compounds is less acidic.

Reason : The anion formed after the loss of $\alpha$-hydrogen atom is resonance stabilised.

Question 45. Assertion : Aromatic aldehydes and formaldehyde undergo Cannizaro reaction.

Reason : Aromatic aldehydes are almost as reactive as formaldehyde.

Question 46. Assertion : Aldehydes and ketones, both react with Tollen’s reagent to form silver mirror.

Reason : Both, aldehydes and ketones contain a carbonyl group.

Question 47. An alkene ‘A’ (Mol. formula $C_5H_{10}$) on ozonolysis gives a mixture of two compounds ‘B’ and ‘C’. Compound ‘B’ gives positive Fehling’s test and also forms iodoform on treatment with $I_2$ and NaOH. Compound ‘C’ does not give Fehling’s test but forms iodoform. Identify the compounds A, B and C. Write the reaction for ozonolysis and formation of iodoform from B and C.

Question 48. An aromatic compound ‘A’ (Molecular formula $C_8H_8O$) gives positive 2, 4-DNP test. It gives a yellow precipitate of compound ‘B’ on treatment with iodine and sodium hydroxide solution. Compound ‘A’ does not give Tollen’s or Fehling’s test. On drastic oxidation with potassium permanganate it forms a carboxylic acid ‘C’ (Molecular formula $C_7H_6O_2$), which is also formed along with the yellow compound in the above reaction. Identify A, B and C and write all the reactions involved.

Question 49. Write down functional isomers of a carbonyl compound with molecular formula $C_3H_6O$. Which isomer will react faster with HCN and why? Explain the mechanism of the reaction also. Will the reaction lead to the completion with the conversion of whole reactant into product at reaction conditions? If a strong acid is added to the reaction mixture what will be the effect on concentration of the product and why?

Question 50. When liquid ‘A’ is treated with a freshly prepared ammoniacal silver nitrate solution, it gives bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid ‘B’ also forms a white crystalline solid with sodium hydrogensulphite but it does not give test with ammoniacal silver nitrate. Which of the two liquids is aldehyde? Write the chemical equations of these reactions also.