Alkanes conformations Sawhorse and Newman projections and halogenation - Question Bank
1. Which statement best describes the relative stability of butane conformations?
2. The free radical halogenation of alkanes is a method for:
3. Which of the following is NOT a type of strain in molecular conformations?
4. What is the term for the conformation where substituents on adjacent carbons are aligned in the same plane?
5. The energy difference between the chair and boat conformations of cyclohexane is approximately:
6. Which conformation of cyclohexane has higher energy due to the steric repulsion between flagpole hydrogens?
7. What is the main product when n-pentane is subjected to free radical chlorination?
8. In the free radical halogenation of a symmetrical alkane, how many distinct monohalogenated products are possible?
9. The stability order of alkyl carbocations is the same as the stability order of:
10. The stability order of alkyl radicals is:
11. Which of the following is a termination step in the free radical chlorination of methane?
12. What is the primary driving force for the formation of free radicals in halogenation?
13. Which group experiences greater 1,3-diaxial strain in cyclohexane?
14. The interconversion of chair conformations of cyclohexane is called:
15. In the chair conformation of cyclohexane, equatorial bonds are oriented:
16. In the chair conformation of cyclohexane, axial bonds are oriented:
17. The most stable conformation of cyclohexane is the:
18. Which of the following is a synclinal conformation of butane?
19. In the eclipsed conformation of ethane, the electron-electron repulsion between the bonding electrons of adjacent C-H bonds is known as:
20. What is the term for the energy difference between different conformations of a molecule?
21. The halogenation of alkanes with iodine is generally not synthetically useful because:
22. What is the main product of the free radical bromination of isobutane?
23. Why is the selectivity of bromine radicals much higher than chlorine radicals in alkane halogenation?
24. The relative rate of attack on primary, secondary, and tertiary C-H bonds by bromine radical is approximately:
25. The relative rate of attack on primary, secondary, and tertiary C-H bonds by chlorine radical is approximately:
26. Why is the secondary hydrogen in propane more likely to be substituted than the primary hydrogen during free radical chlorination?
27. What is the primary product when propane is chlorinated under UV light?
28. Which halogen is least reactive and requires more forcing conditions for free radical substitution of alkanes?
29. Which halogen is most reactive in the free radical substitution of alkanes?
30. During the free radical chlorination of methane, what is the relative rate of substitution of hydrogen atoms in the order primary:secondary:tertiary?
31. Which step terminates the free radical chain reaction in alkane halogenation?
32. Which step is the propagation step in the free radical halogenation of methane?
33. Which step is the first step in the free radical halogenation of methane with chlorine?
34. What is required to initiate the free radical halogenation of alkanes?
35. The halogenation of alkanes typically proceeds via which mechanism?
36. Which of the following reactions is characteristic of alkanes?
37. The staggered conformation where the largest groups are 60 degrees apart is called:
38. The staggered conformation where the largest groups are 180 degrees apart is called:
39. The eclipsed conformation where the largest groups are directly aligned is called:
40. Which projection method explicitly shows the dihedral angles between substituents on adjacent carbons?
41. In a Sawhorse projection, the bonds are viewed from which angle?
42. What is the primary reason for the difference in stability between eclipsed and staggered conformations?
43. The 'gauche' conformation of butane is a type of which broader conformational class?
44. In the Newman projection of butane, which conformation has the two methyl groups positioned 180 degrees apart?
45. The 'anti' conformation of butane is a type of which broader conformational class?
46. Which conformation of ethane has the highest potential energy?
47. What is the dihedral angle between hydrogens on adjacent carbons in the staggered conformation of ethane?
48. In the Newman projection of ethane, what is the dihedral angle between hydrogens on adjacent carbons in the eclipsed conformation?
49. Which conformation of ethane is the most stable?