Alcohols, Phenols and Ethers Mock Test – Class 12 Chemistry

1. A sample of ethanol is oxidised to ethanal with an yield. The ethanal obtained is then oxidised to ethanoic acid with a yield. What mass of ethanoic acid is produced? Use and .

2. A learner proposes converting chlorobenzene directly into phenol through an ordinary reaction at the aromatic carbon. The proposal is weak mainly because:

3. A reactor receives of and of for methanol synthesis. Assuming complete reaction of the limiting reactant, the methanol formed and carbon monoxide remaining are:

4. Phenol is first converted into anisole and then subjected to controlled nitration. The principal less-crowded nitration product is:

5. The final acidification step in the Reimer-Tiemann reaction mainly:

6. Reduction of propanone produces:

7. The major product obtained when propene undergoes hydration in the presence of dilute acid is:

8. Reaction X introduces a carboxyl group into sodium phenoxide using carbon dioxide. Reaction Y introduces a formyl group into phenol using chloroform and aqueous sodium hydroxide. Which identification is correct?

9. Benzyl alcohol may give rapid turbidity with Lucas reagent even though it is classified as a primary alcohol because:

10. A Lewis structure shows a central oxygen atom bonded by single bonds to two carbon groups, with two lone pairs remaining on oxygen. This arrangement represents:

11. Four compounds are described below.
P: on an carbon next to
Q: on an carbon next to an aromatic ring
R: directly on an alkene carbon
S: directly on an aromatic-ring carbon
The sequence P, Q, R, and S corresponds to:

12. Assertion: Many azo-coupling products of phenol are strongly coloured.
Reason: The azo linkage connects conjugated aromatic systems and permits extensive electron delocalisation.

13. Identify the row in which all three classifications agree with the structure.

14. A sample is described as a colourless crystalline substance with a characteristic odour, limited water solubility, and greatly increased solubility in aqueous alkali. The substance is most consistent with:

15. Fermentation of of glucose proceeds with an yield. What mass of ethanol and amount of carbon dioxide are obtained? Use and .

16. Ethylene glycol is the common name of:

17. Assertion: Lower-temperature acid treatment of a suitable primary alcohol may favour ether formation, whereas higher temperature favours alkene formation.
Reason: Ether formation is an intermolecular substitution process, while alkene formation is an elimination process that becomes increasingly favoured at higher temperature.

18. Which reagent sequence converts pentan-3-one into 3-methylpentan-3-ol?

19. Gas evolved from an active glucose fermentation vessel turns limewater milky. This observation supports the formation of:

20. Assertion: -Nitrophenol has a higher boiling point and lower volatility than -nitrophenol.
Reason: -Nitrophenol forms stronger intermolecular hydrogen-bonded associations, whereas -nitrophenol is stabilised mainly by intramolecular hydrogen bonding.

21. A student wishes to prepare ethanal from ethanol using acidified potassium dichromate. The best procedure is to:

22. Match each compound in Column I with its description in Column II.

23. A graph shows concentration against time during reflux oxidation of a primary alcohol with excess oxidising agent. Curve P rises briefly and then falls, while curve Q rises continuously and finally levels off. The most reasonable identities of P and Q are:

24. A reagent that can distinguish phenol from ethanol without using sodium metal is:

25. In neutral alcohols, phenols, and ethers, oxygen normally shows a valency of ______.

26. To convert bromoethane into ethene through an alcohol intermediate, use:

27. Diphenyl ether, , belongs to the category of:

28. Peroxide formation in a stored ether is chemically classified as:

29. Addition of dilute hydrochloric acid to an aqueous solution of sodium phenoxide produces:

30. Complete the controlled oxidation equation:

31. Direct acid-catalysed esterification is often slower with a highly hindered tertiary alcohol than with a comparable primary alcohol because:

32. Identify the row that gives a consistent description of the oxygen centre.

33. Assertion: is an allylic alcohol.
Reason: Its hydroxyl group is attached directly to an -hybridised alkene carbon.

34. A graph plots relative alkene stability against the number of alkyl groups directly attached to the carbon-carbon double bond. The expected general trend is:

35. Which sequence correctly represents the principal stages of acid-catalysed alkene hydration?

36. An ether generally has a lower boiling point than its isomeric alcohol because ether molecules:

37. A graph plots boiling point against carbon number for methanol, ethanol, propan-1-ol, butan-1-ol, and pentan-1-ol. The expected overall trend is:

38. A stored ether contains a small amount of nonvolatile peroxide. Half of the ether solvent evaporates while the peroxide remains. The peroxide concentration will approximately:

39. For the formula , the numbers of saturated acyclic alcohol isomers and ether isomers are, respectively:

40. When 3,3-dimethylbutan-2-ol reacts through a carbocation pathway with concentrated , a rearranged product may form because:

41. Consider the following statements about phenol and quinone oxidation chemistry.
Statement I: Phenol oxidation is structurally different from oxidation of a primary aliphatic alcohol.
Statement II: Quinones contain conjugated carbonyl groups and are often coloured.
Statement III: Reduction of -benzoquinone produces ordinary phenol.

42. Increasing pressure favours methanol formation in the equilibrium

because:

43. Identify the row in which the common name, systematic name, and positional description all agree.

44. A practical record for compound X shows:
- no appreciable oxidation with acidified dichromate under mild conditions;
- dissolution in aqueous sodium hydroxide;
- a coloured response with neutral ferric chloride;
- no carbon dioxide with sodium bicarbonate.

Compound X is:

45. The valid comparison of ester-forming reactions is:

46. Assertion: and have different IUPAC names.
Reason: The methoxy group is attached to different positions of the propane parent chain.

47. Consider the following statements about alcohol nomenclature.
Statement I: The hydroxyl group receives the lowest possible locant in the parent chain.
Statement II: The terminal of the corresponding alkane name is normally dropped before .
Statement III: Numbering begins from the end nearest an alkyl substituent even when this gives a higher locant.

48. Consider the following statements about branching and alcohol solubility.
Statement I: Among alcohol isomers with the same molecular formula, branching can increase water solubility by making the hydrophobic carbon skeleton more compact.
Statement II: Branching does not change the number of hydroxyl groups in structural isomers being compared.
Statement III: Every branched alcohol is insoluble in water.

49. During electrophilic attack on phenol, an intermediate formed by substitution at an ortho or para position receives special stabilisation because:

50. Thionyl chloride is often preferred for preparing a pure alkyl chloride from an alcohol because its by-products are: