MCQ cycloalkanes 3rd Semester B.pharmacy

MULTIPLE CHOICE QUESTIONS Of cycloalkanes chapter of Pharmaceutical Organic Chemistry 3rd semester B.Pharmacy.

1. Identify the formula for cycloalkanes

  • a) C₂H₂n+2
  • b) CnH₂(n+2)
  • c) C₂H₂n
  • d) CnH₂(n–2)

Answer- c) C₂H₂n

2. Cycloalkanes have same boiling and melting points as their corresponding alkanes state true or false

  • a) False
  • b) True

Answer- a) False

  • 3. Identify the incorrect statement
  • a) Cycloalkanes have sp’ hybridized carbons
  •  b) Cycloalkanes have tetrahedral bond angles
  • c) Stability of the cycloalkanes varies directly with their respective size
  • d) Cycloalkanes under nucleophillic substitution reactions

Answer- b) Cycloalkanes have tetrahedral bond angles

4. Which of the following compound have highest ring strain

  • a) Cyclopropane
  • b) Cyclobutane
  • c) Cyclopentane
  • d) Cyclomethane

Answer- a) Cyclopropane

5. Which of the following cycloalkanes has the least ring strain?

  • a) Cyclopropane
  • b) Cyclohexane
  • c) Cyclopentane
  • d) Cycloheptane

Answer- b) Cyclohexane

6. In which of the following compounds all of the carbon atoms in the same plane?

  • a) Cyclopropane
  • b) Cyclobutane
  • c) Cyclohexane
  • d) Cyclopentane

Answer- a) Cyclopropane

7. Which of the following cycloalkanes has the largest heat combustion per carbon atom?

  •  a) Cyclopentane
  • b) Cyclohexane
  • c) Cycloheptane
  • d) Cyclopropane

Answer- d) Cyclopropane

8. Which of the following cycloalkanes has the lowest heat of combustion per carbon atom?

  • a) Cyclopropane.
  • b) Cyclopentane
  • c) Cyclohexane
  • d) Cycloheptane

Answer- c) Cyclohexane

9. Which of the following method is most suitable for the preparation of cyclopropane?

  • a) Dieckmann condensation
  • b) Freund’s method
  • c) Diel’s Alder reaction
  • d) None of above

Answer- b) Freund’s method

10. Which of the following reaction not occur in thermal conditions?

  •  a) [2+2] cyclo addition reaction
  • b) [4+2] cyclo addition reaction
  • c) [2+1] cyclo addition reaction
  • d) [4+1] cyclo addition reaction

Answer- a) [2+2] cyclo addition reaction

11. Which of the following compound is obtained when alkene is treated with CH2I2 and Zn Cu couple?

  • a) Cyclobutane
  • b) Cyclohexane
  • c) Cyclopropane
  • d) Cycloheptane

Answer- c) Cyclopropane

12. Which of the following method is suitable for the preparation of higher ring compounds?

  • a) Simmon’s-Smith reaction
  • b) Wislicenus method
  • c) Hydrogenation of aromatic compound
  • d) Thorpe-Zieglar reaction

Answer- d) Thorpe-Zieglar reaction

13. Name the method by which cyclic ketones is converted into cycloalkanes in presence of Zn amulgum and Conc. HCI

  • a) Wolff-Kishmer reduction
  • b) Clemmensen’s reduction
  • c) Diel’s Alder reaction
  • d) None of above

Answer- b) Clemmensen’s reduction

14. Choose the incorrect statement

  • a) Cycloalkanes have high boiling and melting point then alkanes
  • b) Cyclopropane and cyclobutane are gases while higher members are liquids
  • c) Cycloalkanes are insoluble in water
  • d) Cyclo alkanes are insoluble in non-polar solvent

Answer- d) Cyclo alkanes are insoluble in non-polar solvent

15.  Cyclopropane when reacted with Bromine it gives

  • a) 1,2-dibromopropane
  • b) 1,3-dibromopropane
  • c) 1,4-dibromopropane
  • d) 1,1-dibromopropane

Answer- b) 1,3-dibromopropane

16. In a cycloalkanes what is the difference between torsional and angle strain?

  • a) Torsional strain refer to size of the ring, angle strain refers to unfavorable orbital overlap
  • b) Torsional strain rewfer to the size of the ring, angle strain refers to eclipsed CH₂ groups
  • c) Torsional strain refer to eclipsed CH₂ groups, angle strain refers to the C-C-H bond angles
  • d) Torsional strain refers to eclipsed CH, group, angle strain refer to unfavorable orbital overlap

Answer- d) Torsional strain refers to eclipsed CH, group, angle strain refer to unfavorable orbital overlap

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