Intro to Substitution Reactions - Crash Course Organic Chemistry

The video explores the historical development of chemotherapy from mustard gas used in World War I, highlighting its transformation into cancer treatment drugs. It delves into the chemistry of substitution reactions, focusing on SN1 and SN2 mechanisms, their differences, and their applications in medicine, particularly in chemotherapy. The video explains how these reactions work at a molecular level, using analogies and detailed mechanisms to illustrate the processes.

What was an unexpected benefit of sulfur mustard discovered after World War I?

• It improved air quality.

• It could be used as a fuel.

• It had anti-carcinogenic effects.

• It was a powerful disinfectant.

What is the main difference between addition reactions and substitution reactions?

• Addition reactions occur only in inorganic chemistry.

• Addition reactions are faster than substitution reactions.

• Addition reactions involve pi bonds, substitution reactions involve nucleophiles.

• Addition reactions remove atoms, substitution reactions add atoms.

In an SN1 reaction, what is the rate-determining step?

• Formation of the carbocation.

• Deprotonation of the substrate.

• Formation of the nucleophile.

• Nucleophilic attack.

What happens to the stereochemistry in an SN1 reaction?

• It always inverts.

• It remains unchanged.

• It can be the same or inverted.

• It forms a racemic mixture.

Which type of substrate is preferred in SN1 reactions?

• Tertiary substrates.

• Quaternary substrates.

• Primary substrates.

• Secondary substrates.

In an SN2 reaction, what role does the nucleophile play?

• It acts as a catalyst.

• It stabilizes the leaving group.

• It forms a carbocation.

• It performs a backside attack.

What is a characteristic feature of SN2 reactions?

• They occur in a concerted process.

• They involve a carbocation intermediate.

• They are unimolecular.

• They always form racemic mixtures.

How do SN2 reactions affect stereochemistry?

• They have no effect on stereochemistry.

• They invert the stereochemistry.

• They retain the stereochemistry.

• They create a racemic mixture.

What is the role of nitrogen mustard in chemotherapy?

• It repairs damaged cells.

• It cross-links DNA strands.

• It acts as a pain reliever.

• It enhances DNA replication.

Which mechanism is favored by primary and secondary substrates?

• SN1 mechanism.

• SN2 mechanism.

• Both SN1 and SN2.

• Neither SN1 nor SN2.