Question 1

Which of the following statements best describes a chiral molecule?

Accepted Answer

A molecule that is not superposable on its mirror image.

Question 2

Which of the following molecules would be expected to be achiral?

Accepted Answer

A molecule with a plane of symmetry.

Question 3

How many stereoisomers are possible for a molecule with three chiral centers, assuming no meso forms?

Accepted Answer

$$2^3 = 8$

Question 4

Which of the following best describes enantiomers?

Accepted Answer

Stereoisomers that are nonsuperposable mirror images of each other.

Question 5

A molecule with two chiral centers is found to be achiral. What is the most likely explanation?

Accepted Answer

The molecule is a meso compound.

Question 6

Which of the following is true about the R, S system for naming chiral centers?

Accepted Answer

R means the order of priority is clockwise.

Question 7

Which of the following is a correct application of the Cahn-Ingold-Prelog priority rules?

Accepted Answer

A -CH2Cl group has higher priority than a -CH2CH2CH3 group.

Question 8

Which of the following statements about meso compounds is FALSE?

Accepted Answer

Meso compounds are optically active.

Question 9

Which of the following best describes diastereomers?

Accepted Answer

Stereoisomers that are not mirror images of each other.

Question 10

Which of the following molecules is most likely to exhibit atropisomerism?

Accepted Answer

A molecule with a hindered rotation around a single bond.

Question 11

Which of the following statements about enantiomers is correct?

Accepted Answer

Enantiomers have identical physical and chemical properties in an achiral environment.

Question 12

How many stereoisomers are possible for 2,3-dihydroxybutanedioic acid (tartaric acid)?

Accepted Answer

3

Question 13

Which of the following best describes a Fischer projection?

Accepted Answer

A two-dimensional projection where horizontal groups are in front and vertical groups are behind the plane.

Question 14

Which of the following is true for cis-1,2-cyclopentanediol?

Accepted Answer

It is a meso compound.

Question 15

A sample of tartaric acid is found to have a specific rotation of $$+12.7^\circ. $$Which stereoisomer is it most likely to be?

Accepted Answer

$$(2R,3R)-$$tartaric acid

Question 16

Which of the following statements about conformational isomers is correct?

Accepted Answer

They can be interconverted by rotation around single bonds.

Question 17

Which of the following is NOT a criterion for assigning priority in the Cahn-Ingold-Prelog system?

Accepted Answer

Molecular weight of the entire molecule.

Question 18

Which of the following best describes the relationship between cis- and trans-2-butene?

Accepted Answer

They are diastereomers.

Question 19

Which of the following molecules would be expected to have a center of symmetry?

Accepted Answer

A molecule with identical groups located equidistant and on opposite sides from a central point.

Question 20

Which of the following is a correct statement about the number of stereoisomers for a molecule with two chiral centers, if a meso form is possible?

Accepted Answer

There will be three stereoisomers: a pair of enantiomers and one meso compound.

Stereoisomerism and Chirality: A Comprehensive Study Guide

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