Organic Chemistry Mock Test – Class 11 Chemistry

1. An analytical case has carbon, hydrogen, nitrogen, and oxygen in a sample. What empirical formula follows?

2. Consider the statements about reaction classification.
Statement I: Addition usually increases bonding at the atoms of a multiple bond.
Statement II: Elimination often forms a multiple bond by removing a small molecule.
Statement III: Substitution means two groups add across a double bond without any group leaving.
Which statements are valid?

3. A formula is given for an open-chain hydrocarbon with one carbon-carbon multiple bond. The most suitable family is:

4. Which name-formula pair is correctly matched for a straight-chain alkane?

5. A substituent shows effect because of electronegativity but effect because of lone-pair donation into a ring. Which group best fits this description when attached to benzene?

6. A formula is assigned to an ester named . What mass percentage of oxygen does this formula contain? Use , , and .

7. A compound is known to contain exactly one functional group and has the molecular formula . Two possible structures are and . What is the best comparison?

8. A compound is an acyclic monoalkene. of reacts with of . Another sample on combustion gives . Which formula is consistent with both results?

9. The carboxylate ion, , can be represented by two equivalent resonance forms. In one form, one oxygen is double-bonded to carbon and the other oxygen carries the negative charge; in the other form, these roles are interchanged. What does this imply about the two carbon-oxygen bonds in the carboxylate group?

10. In paper chromatography, water held on cellulose fibres often acts as the stationary phase. This makes the method closer to:

11. A comparison of , , and is used to introduce single, double, and triple bonding. The feature common to the carbon atoms in all three examples is that:

12. When a compound has both and prefixes, the prefixes are arranged alphabetically in the name. Which name follows this rule correctly?

13. An organic compound is analysed as follows: carbon and hydrogen are found by combustion, nitrogen by Dumas method, and chlorine by Carius method. Oxygen is then calculated by difference. Which condition is essential for the oxygen-by-difference step?

14. Another mixture contains ethanol and propanone , with oxygen in total. What mass of ethanol is present?

15. A compound contains a five-carbon parent chain, a double bond starting at carbon , and a methyl group at carbon . The suitable name is:

16. Consider the following statements about nitrogen-containing functional groups.
Statement I: attached to an alkyl group gives an amine.
Statement II: gives an amide.
Statement III: gives a nitro compound.
Which statements are valid?

17. The condensed formulas and have the same molecular formula . Their difference is best described as:

18. In a group-priority decision, a structure contains and on the same carbon chain. The naming approach should first recognise:

19. Read the case below and answer the question.

What is the best reason for the note?

20. A solute has . A aqueous solution is extracted either once with organic solvent or three times with portions. What fraction of the original solute remains in water in the more efficient method?

21. A pair of compounds has the same formula . Pair I is and . Pair II is and . The correct comparison is:

22. A formula can represent or . What type of difference is present?

23. A sample of an organic compound gives of dry at by the Dumas method. If the sample mass is , what is the percentage of nitrogen? Use at as .

24. A Carius analysis of of an organic compound containing only chlorine as halogen gives of . What percentage of chlorine is present? Use and .

25. A hydrocarbon has formula , is open-chain, and contains one bond. Two structures are and . What type of isomerism is shown?

26. A structure is written as . What is the correct parent chain length for IUPAC naming?

27. A compound contains , , and . Its molar mass is . What is its molecular formula?

28. The structure is named by selecting the longest chain and identifying the branch. The correct name is:

29. A student says that the component with the largest value is always the most polar compound. The best evaluation is:

30. A reagent approaches a molecule containing . Once the reagent is removed before reaction, the temporary electron displacement disappears. Which effect is being described?

31. A molecule is described as . The part and the part are best described as:

32. A graph is drawn for an empirical-formula calculation. The horizontal axis shows the calculation stage: mass of element, moles of element, divided ratio, and whole-number ratio. The graph shows a sharp change between mass and moles for chlorine compared with hydrogen. What is the best reason?

33. Count the number of alpha bonds available for hyperconjugation in the carbocation . The positively charged carbon is attached to two groups and one .

34. Consider the following carbon frameworks:

What do all three frameworks show?

35. Assertion: is stronger than .
Reason: The group withdraws electron density and stabilises the carboxylate ion more than .

36. The structure is best named as:

37. Consider the following statements about functional groups.
Statement I: in is a hydroxy group.
Statement II: in is an ether linkage.
Statement III: and represent the same functional group because both contain oxygen.
The valid statements are:

38. A compound contains , , , and . Analysis gives , , and . What percentage of oxygen is present?

39. A neutral molecule can act as a nucleophile when it has:

40. In the molecule , the hybridisation of the three carbon atoms from left to right is:

41. A compound contains . What is the most suitable functional-group class?

42. The condensed formula is best interpreted as:

43. In Carius estimation of sulfur, sulfur in the organic compound is finally converted into and weighed as:

44. A compound containing only , , and gives and from sample. A separate Carius estimation gives from sample. What empirical formula is obtained? Use , , , and .

45. A hydrocarbon name is proposed as . What structural information must be true?

46. A molecule has a carbon chain and a terminal group . What is the most suitable family classification?

47. An alkyl group is formed when one hydrogen atom is removed from an alkane. If the parent alkane has the formula , the general formula of the corresponding monovalent alkyl group is:

48. Consider the following statements about substitutive nomenclature.
Statement I: A halogen substituent is usually named with a prefix such as or .
Statement II: A nitro group is usually named with the prefix .
Statement III: A carboxylic acid group is normally ignored when a nitro group is present.
Which statements are valid?

49. Study the table and identify the unsuitable entry.

50. In a separating funnel containing ether and water, the organic layer is not always the upper layer. The layer position must be decided mainly from: