Geometrical isomerism and E-Z nomenclature for double bonds - One Line Questions

1. What is the priority of -CH2CH3 compared to -CH3 according to Cahn-Ingold-Prelog rules? — -CH2CH3 has higher priority.
2. What is the priority order of the following groups according to Cahn-Ingold-Prelog rules: -OH, -CH3, -NH2, -F? — -F > -OH > -NH2 > -CH3
3. What is the priority of -SH compared to -OH using Cahn-Ingold-Prelog rules? — -SH has higher priority.
4. Which of the following is correctly named using cis-trans nomenclature? — 1,2-dibromoethene
5. Which of the following pairs are geometrical isomers? — cis-2-Butene and trans-2-Butene
6. Which of the following molecules cannot exhibit geometrical isomerism? — 1,1-diphenylethene
7. A molecule that exhibits geometrical isomerism has: — A double bond (or ring system) with restricted rotation and different groups on at least one of the carbons involved.
8. Geometrical isomerism in cyclic compounds occurs when substituents are on: — Adjacent carbon atoms in the ring
9. Consider 1-bromo-1-chloropropene. How would you determine the priority of the groups on the double bond carbons? — Assign priority based on the Cahn-Ingold-Prelog rules, starting with atomic number.
10. What is the fundamental requirement for a molecule to exhibit geometrical isomerism around a double bond? — Both carbon atoms of the double bond must be attached to two different groups.
11. The Cahn-Ingold-Prelog priority rules state that if the atoms directly attached to the points of comparison are the same, one moves to the next atoms until a point of difference is found. This is known as: — Sequential comparison of atoms
12. What is the primary difference in physical properties between cis and trans isomers? — All of the above
13. In the E/Z system, what is the priority of Br compared to Cl? — Br has higher priority than Cl.
14. Consider 3-methylpent-2-ene. The substituents on C2 are CH3 and H. The substituents on C3 are CH3 and CH2CH3. What is the priority order on C2 and C3 respectively? — CH3 > H and CH2CH3 > CH3
15. What is the product of the reduction of an alkyne with sodium in liquid ammonia (dissolving metal reduction)? — Trans alkene
16. The stability of geometrical isomers is generally such that: — Trans isomers are more stable than cis isomers.
17. Which factor makes geometrical isomers different from each other? — Spatial arrangement of atoms
18. What is the relationship between cis-2-butene and trans-2-butene? — Diastereomers (specifically, geometrical isomers)
19. If a molecule can exist as cis and trans isomers, these isomers are also known as: — Diastereomers
20. For 1-bromo-1-chloropropene, if Br and CH3 are on the same side, and Cl and H are on the same side, what is the configuration? — Z
21. For 1-bromo-1-chloropropene, if Br and H are on the same side, and Cl and CH3 are on the same side, what is the configuration? — E
22. Apply E/Z nomenclature to 2-bromobut-2-ene. What is the configuration? — E
23. Apply E/Z nomenclature to 3-methylpent-2-ene. What is the configuration? — Z
24. In the E/Z system, if the two higher priority groups are on opposite sides of the double bond, the configuration is: — E
25. In the E/Z system, if the two higher priority groups are on the same side of the double bond, the configuration is: — Z
26. For 3-methylpent-2-ene, if the two higher priority groups (CH3 on C2 and CH2CH3 on C3) are on the same side, what is the configuration? — Z
27. For 3-methylpent-2-ene, if the two higher priority groups (CH3 on C2 and CH2CH3 on C3) are on opposite sides, what is the configuration? — E
28. Which of the following is a correct application of the E/Z nomenclature? — Z-1,2-dibromoethene
29. Geometrical isomerism requires restricted rotation. Which of the following exhibits restricted rotation? — Ethene
30. Which of the following molecules can exhibit geometrical isomerism? — 1,2-Dichloroethene (CHCl=CHCl)
31. Consider the molecule CH3-CH=C(Br)-Cl. What is the configuration of this molecule? — It can be either E or Z.
32. Geometrical isomers have different: — Physical properties
33. Consider 1,2-dimethylcyclopentane. This molecule exhibits geometrical isomerism. What are the possible configurations? — Both cis and trans
34. Consider 1-bromo-2-chlorocyclopentene. Which isomers can exist? — Both cis and trans isomers
35. In the cis-trans nomenclature system, 'cis' refers to isomers where similar groups are on: — The same side of the double bond
36. In the E/Z nomenclature, 'Z' (from German 'zusammen') indicates that the higher priority groups are on: — The same side of the double bond
37. Which type of isomerism arises due to restricted rotation around a double bond? — Geometrical isomerism
38. Which type of isomerism is exhibited by 1,2-dibromocyclohexane? — Geometrical isomerism
39. Geometrical isomerism is also known as: — Cis-trans isomerism
40. Which geometrical isomer generally has a higher melting point? — The trans isomer
41. In the cis-trans nomenclature system, 'trans' refers to isomers where similar groups are on: — Opposite sides of the double bond
42. In the E/Z nomenclature, 'E' (from German 'entgegen') indicates that the higher priority groups are on: — Opposite sides of the double bond
43. The E/Z nomenclature system is based on the priority of substituents determined by: — Their atomic number (Cahn-Ingold-Prelog rules)
44. Why do trans isomers often have higher melting points than cis isomers? — They pack more efficiently into a crystal lattice.
45. Consider the reaction of an alkyne with H2 in the presence of Lindlar's catalyst. What type of alkene is formed and what is its configuration? — Cis alkene, Z configuration
46. Why are trans isomers generally more stable than cis isomers? — Trans isomers have less steric hindrance.
47. When is the cis-trans nomenclature system preferred over the E/Z system? — When there are only two different substituents on each carbon of the double bond.
48. The E/Z nomenclature is essential when cis-trans nomenclature is ambiguous. When does ambiguity arise in cis-trans nomenclature? — When there are three or more different substituents on at least one of the double bond carbons.
49. Can cyclopropane exhibit geometrical isomerism? — No, it lacks a double bond.
50. For a molecule like 2-methyl-2-butene (CH3-C(CH3)=CH-CH3), can it exhibit geometrical isomerism? — No, because one carbon of the double bond has two identical methyl groups.
All One Line Questions
E-Book Geometrical isomerism and E-Z nomenclature for double bonds Online Test Geometrical isomerism and E-Z nomenclature for double bonds Question Bank Geometrical isomerism and E-Z nomenclature for double bonds