Substitution Reactions - SN1 and SN2 Mechanisms - Crash Course Organic Chemistry

The video tutorial covers the basics of dry cleaning, its environmental impact, and the chemistry behind SN1 and SN2 reactions. It explains the role of substrates, leaving groups, and nucleophiles in substitution reactions, and how factors like substrate structure, nucleophile strength, and solvent type influence the reaction mechanism. The tutorial also provides practical examples and tips for determining the likely reaction pathway.

What is the primary environmental concern associated with tetrachloroethylene used in dry cleaning?

• It can cause water pollution.

• It is non-biodegradable.

• It is highly flammable.

• It is a greenhouse gas.

Which of the following is a characteristic of an SN1 reaction?

• Requires strong nucleophiles

• Inversion of stereochemistry

• Carbocation intermediate

• Concerted mechanism

Which of the following is a poor leaving group?

• Chloride

• Hydroxide

• Bromide

• Tosylate

What type of substrate is most likely to undergo an SN2 reaction?

• Primary carbon

• Secondary carbon

• Vinyl carbon

• Tertiary carbon

Which substrate structure is least likely to undergo an SN2 reaction?

• Allylic carbon

• Tertiary carbon

• Secondary carbon

• Primary carbon

Which nucleophile is considered strong and likely to participate in an SN2 reaction?

• Water

• Methanol

• Acetic acid

• Hydroxide ion

What is a common feature of strong nucleophiles?

• They are typically neutral molecules.

• They are weak bases.

• They are large and polarizable.

• They are often uncharged.

How do polar protic solvents influence SN1 reactions?

• They increase the nucleophile strength.

• They favor the formation of a concerted mechanism.

• They stabilize the carbocation intermediate.

• They prevent the reaction from occurring.

What is the effect of a polar aprotic solvent on an SN2 reaction?

• It enhances nucleophilicity.

• It weakens the nucleophile.

• It stabilizes the carbocation.

• It prevents the reaction.

Which solvent type is most likely to favor an SN2 reaction?

• Polar protic

• Non-polar

• Polar aprotic

• Aqueous