Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

3. Acids and Bases

Reaction Mechanism

Organic Chemistry

3. Acids and Bases

Reaction Mechanism

Previous problemNext problem

Struggling with Organic Chemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

Which is the correct depiction of the transition state for the SN2 reaction shown below?

A tetrahedral transition state with no partial bonds.

A pentacoordinate transition state with partial bonds to the nucleophile and leaving group.

A trigonal planar transition state with full bonds to the nucleophile and leaving group.

A linear transition state with full bonds to the nucleophile and leaving group.

Previous problemNext problem

Verified step by step guidance

Understand the SN2 reaction mechanism: SN2 stands for bimolecular nucleophilic substitution. It involves a single step where the nucleophile attacks the electrophilic carbon, leading to the simultaneous displacement of the leaving group.

Recognize the transition state characteristics: In an SN2 reaction, the transition state is characterized by a pentacoordinate structure. This means the central carbon is temporarily bonded to five groups: the nucleophile, the leaving group, and the three other substituents.

Identify partial bonds in the transition state: During the transition state, the nucleophile forms a partial bond with the central carbon, while the leaving group also maintains a partial bond. This is due to the simultaneous bond formation and bond breaking.

Visualize the geometry: The transition state in an SN2 reaction is not tetrahedral or trigonal planar. Instead, it is a trigonal bipyramidal structure, where the nucleophile and leaving group are positioned opposite each other, creating partial bonds.

Consider the stereochemistry: SN2 reactions are known for their stereospecificity, leading to an inversion of configuration at the carbon center. This is due to the backside attack of the nucleophile, which is consistent with the pentacoordinate transition state.