Stereochemistry: Enantiomers

Professor Dave explains the concept of stereoisomers, focusing on enantiomers and chirality. He begins with an overview of isomerism, distinguishing between structural isomers and stereoisomers. The video delves into enantiomers, which are non-superposable mirror images, using hands as an analogy. Chirality is introduced, highlighting the importance of a carbon atom with four different substituents. Examples illustrate how to identify chiral and achiral molecules, emphasizing the role of mirror images in determining chirality.

What distinguishes structural isomers from other types of isomers?

• They are non-superposable mirror images.

• They have different molecular formulas.

• They have the same connectivity but different spatial orientation.

• They have the same molecular formula but different connectivity.

Which of the following best describes enantiomers?

• Molecules that are non-superposable mirror images.

• Molecules with the same connectivity but different spatial orientation.

• Molecules that are superposable mirror images.

• Molecules with different molecular formulas.

What is the term used to describe a molecule with a non-superposable mirror image?

• Achiral

• Symmetric

• Chiral

• Isomeric

What is a chiral center in a molecule?

• A carbon atom with two identical and two different substituents.

• A carbon atom with no substituents.

• A carbon atom with four different substituents.

• A carbon atom with four identical substituents.

How can you determine if a molecule is achiral?

• Its mirror image is superposable.

• It has four different substituents.

• Its mirror image is non-superposable.

• It has a chiral center.

What prefix is used to indicate a molecule is not chiral?

• Un-

• A-

• Anti-

• Non-

Which of the following statements is true about a molecule with two identical substituents?

• It has a chiral center.

• It is always achiral.

• It cannot have an enantiomer.

• It is always chiral.