Understanding Optical Activity and Stereochemistry

What happens to plane polarized light when it passes through a solution containing a chiral compound?

• It gets absorbed completely.

• It remains unchanged.

• It gets rotated in one direction.

• It splits into two beams.

How do achiral compounds affect plane polarized light?

• They absorb it completely.

• They do not rotate it at all.

• They rotate it to the right.

• They rotate it to the left.

What is the main difference between absolute and relative configurations?

• Neither can be determined by structure alone.

• Both can be determined by structure alone.

• Relative configurations can be determined by structure alone.

• Absolute configurations can be determined by structure alone.

Which of the following is true about relative configurations?

• They can be determined by looking at the molecular structure.

• They require a polarimeter to be determined.

• They are the same as absolute configurations.

• They are not related to optical activity.

What is specific rotation?

• The speed at which light travels through a chiral compound.

• The angle of rotation of light by a chiral compound under standard conditions.

• The temperature at which a chiral compound melts.

• The wavelength of light absorbed by a chiral compound.

Which units are used for concentration in the specific rotation formula?

• Grams per liter

• Moles per milliliter

• Moles per liter

• Grams per milliliter

In the specific rotation calculation, what is the path length measured in?

• Meters

• Millimeters

• Centimeters

• Decimeters

What does an optical purity of 0.5 indicate about a mixture?

• It is optically inactive.

• It contains only one enantiomer.

• There is 50% more of one enantiomer than the other.

• It is a racemic mixture.

How is enantiomeric excess related to optical purity?

• Enantiomeric excess is always half of optical purity.

• They are unrelated.

• Optical purity is always double the enantiomeric excess.

• They are equal to each other.

If a mixture has an observed specific rotation of -11.5 degrees, what can be inferred?

• There is more of the R enantiomer.

• There is more of the S enantiomer.

• It is a racemic mixture.

• It is optically inactive.