Nucleophiles, Electrophiles, Leaving Groups, and the SN2 Reaction

Professor Dave explains the SN2 reaction, a type of nucleophilic substitution where a nucleophile replaces a leaving group on a substrate. The video covers the key players: nucleophile, electrophile, and leaving group, and details the reaction mechanism, emphasizing the importance of electron-pushing arrows. It also discusses the geometric aspects, including the transition state and stereochemistry inversion, highlighting the bimolecular nature of the SN2 reaction.

What is the role of a nucleophile in an SN2 reaction?

• It acts as a leaving group.

• It stabilizes the transition state.

• It accepts electron density from the electrophile.

• It donates electron density to the electrophile.

What is the role of the leaving group in an SN2 reaction?

• It donates electrons to the nucleophile.

• It stabilizes the nucleophile.

• It departs, allowing the nucleophile to form a new bond.

• It increases the reaction rate.

Why is it important to draw electron-pushing arrows correctly in SN2 mechanisms?

• They indicate the direction of nucleophile movement.

• They show the flow of electron density.

• They identify the leaving group.

• They determine the reaction speed.

In an SN2 reaction, what is the significance of a back side attack?

• It ensures the nucleophile approaches from the same side as the leaving group.

• It allows the nucleophile to approach from the opposite side of the leaving group.

• It stabilizes the electrophile.

• It increases the reaction rate.

What does the '2' in SN2 stand for?

• The number of steps in the reaction.

• The number of molecules involved in the transition state.

• The number of nucleophiles involved.

• The number of leaving groups.

How does the geometry of the substrate change during an SN2 reaction?

• It changes from tetrahedral to trigonal planar.

• It remains unchanged.

• It becomes linear.

• It inverts like an umbrella.

What happens to the stereochemistry at a chiral center during an SN2 reaction?

• It becomes achiral.

• It inverts.

• It becomes racemic.

• It remains the same.