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
