Question 1

Which of the following statements best describes a chiral molecule?

Accepted Answer

A molecule that is not superposable on its mirror image and lacks a plane of symmetry.

Question 2

Which of the following molecules would be expected to be achiral based on the presence of symmetry elements?

Accepted Answer

A molecule with a plane of symmetry passing through it.

Question 3

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

Accepted Answer

$$2^3 = 8$

Question 4

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

Accepted Answer

They are diastereomers.

Question 5

A molecule has two chiral centers and is found to be superposable on its mirror image. What is this molecule called?

Accepted Answer

Meso compound

Question 6

Which of the following is NOT a criterion for assigning priority in the Cahn-Ingold-Prelog (R,S) system?

Accepted Answer

The physical state (solid, liquid, gas) of the substituent.

Question 7

Which of the following statements about enantiomers is correct?

Accepted Answer

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

Question 8

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

Accepted Answer

A molecule with hindered rotation around a bond due to bulky groups.

Question 9

Assign the absolute configuration (R or S) to the following chiral center: $$\mathrm{CH_3CH(Br)Cl}$$, where the priorities are Br \u003e Cl \u003e CH$$_3$$ \u003e H and the lowest priority group (H) is pointing away from you.

Accepted Answer

R

Question 10

Which of the following best describes a meso compound?

Accepted Answer

A compound with two or more chiral centers that is achiral due to a plane of symmetry.

Question 11

Which of the following is a correct statement about diastereomers?

Accepted Answer

They have different physical and chemical properties.

Question 12

How many stereoisomers are possible for 2,3-butanediol?

Accepted Answer

3

Question 13

Which of the following best explains why the cis isomer of 1,2-cyclopentanediol is a meso compound?

Accepted Answer

It has two chiral centers but also a plane of symmetry.

Question 14

Which of the following is true about Fischer projections?

Accepted Answer

Horizontal lines represent bonds coming out of the plane of the paper.

Question 15

A sample of tartaric acid is found to have a specific rotation of $$0^{\circ}. $$Which stereoisomer is most likely present?

Accepted Answer

Meso-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 a real-world application of chirality?

Accepted Answer

The effectiveness of a drug can depend on its chirality.

Question 18

Which of the following best describes the relationship between (2R,3R)-erythrose and (2S,3S)-erythrose?

Accepted Answer

They are enantiomers.

Question 19

Which of the following is true regarding the number of stereoisomers for a molecule with two chiral centers and a plane of symmetry?

Accepted Answer

There are three stereoisomers, including a meso compound.

Question 20

Which of the following best describes the difference between constitutional isomers and stereoisomers?

Accepted Answer

Stereoisomers have the same molecular formula and connectivity but differ in spatial arrangement.

Stereoisomerism and Chirality: Structure, Nomenclature, and Properties

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