M5L14 - MPQ - Ka

A chiral carbon is:

• a carbon atom attached to four different groups

• a carbon atom attached to two hydrogen atoms

• a carbon atom in a double bond

• a carbon atom in a benzene ring

Optical isomerism refers to which of the following?

• A phenomenon where compounds have the same molecular formula but differ in the arrangement of atoms in space, resulting in non-superimposable mirror images.

• A phenomenon where compounds have different molecular formulas but similar structures.

• A phenomenon where compounds have the same structure but different physical states.

• A phenomenon where compounds have the same molecular formula and are superimposable mirror images.

Enantiomers are:

• Molecules that are non-superimposable mirror images of each other

• Molecules with the same molecular formula but different connectivity

• Molecules that are superimposable on their mirror images

• Molecules with different molecular formulas but similar structures

Which of the following correctly represents the 3D structures of the two optical isomers of 2-hydroxy propanoic acid?

• The two isomers are non-superimposable mirror images of each other, each with a chiral center at the second carbon.

• Both isomers have identical 3D structures with no chiral center.

• The two isomers are superimposable and have the same arrangement around the chiral center.

• Both isomers lack a chiral center and are optically inactive.

Which of these molecules has optical isomers?

• 2-chlorobutane

• Butanone

• 1,5-dichloropentane

• 2,4-dichloropentane

How many chiral carbons are there in molecule D (opposite)?

• 2

• 0

• 1

• 3

1. A chiral carbon: _________.

• has 4 different groups attached.

• has only 2 different groups attached.

• is always planar in structure.

• is always found in aromatic compounds.

Optical isomerism is: _________

• molecules that mirror images that are non-superimposable.

• molecules that have the same boiling point.

• molecules that are always planar.

• molecules that have identical chemical properties.

Enantiomers are: _________

• molecules that are mirror images

• molecules that are structural isomers

• molecules that are geometric isomers

• molecules that are identical

3D structures for 2-hydroxy propanoic acid (opposite).

• [Images of 3D structures shown]

• [Images of 3D structures for acetic acid]

• [Images of 3D structures for citric acid]

• [Images of 3D structures for butanoic acid]