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04 Conformation and Stereochemistry Online Quiz Questions

Use this free practice quiz with 20 questions to review 04 Conformation and Stereochemistry, test your knowledge, and prepare for your next test or exam.

20 questions
01
Choose one
1 point

Which statement best describes stereoisomers?

  1. A

    They have different atom-to-atom connectivity but the same spatial arrangement.

  2. B

    They have the same atom-to-atom connectivity but different spatial arrangements.

  3. C

    They differ only in the number of atoms they contain.

02
True or false
1 point

True or false: Every chiral molecule must contain a tetrahedral carbon attached to four different groups.

  1. A

    True

  2. B

    False

03
Choose one
1 point

Which conformation of ethane is more stable, and why?

  1. A

    Eclipsed, because its bonds are aligned.

  2. B

    Staggered, because it has less torsional strain.

  3. C

    Eclipsed, because it has less torsional strain.

04
Fill in the blank
1 point

In butane, the more stable arrangement with the two methyl groups 180° apart is called .

05
True or false
1 point

True or false: During a cyclohexane chair flip, each substituent switches between axial and equatorial while retaining its up-or-down orientation.

  1. A

    True

  2. B

    False

06
Choose one
1 point

Which statement correctly distinguishes conformational change from configurational change?

  1. A

    Conformers differ by connectivity; configurations differ only by rotation around single bonds.

  2. B

    Both conformational and configurational changes always occur by free rotation around single bonds.

  3. C

    Conformers can interconvert by rotation around single bonds, whereas changing configuration generally requires bond breaking or overcoming a barrier to free rotation.

07
Written response
1 point

What is the term for a pair of stereoisomers that are not mirror images of each other?

08
Choose all
1 point

Select all statements that correctly describe enantiomers.

  1. A

    They are nonsuperimposable mirror images.

  2. B

    They have different ordinary physical properties in every achiral environment.

  3. C

    They have the same ordinary physical properties in an achiral environment.

  4. D

    They rotate plane-polarized light in the same direction.

09
Fill in the blank
1 point

A larger substituent on a cyclohexane chair usually favors the position because it reduces steric interactions.

10
Choose one
1 point

An alkene has its higher-priority group on each double-bond carbon on the same side. Which E/Z descriptor applies?

  1. A

    E

  2. B

    Z

  3. C

    R

11
True or false
1 point

An R descriptor tells you that a compound rotates plane-polarized light in a positive direction.

  1. A

    True

  2. B

    False

12
Written response
1 point

When two attached atoms tie in atomic number under CIP rules, what ordering principle is used to compare the atoms attached to them?

13
Choose all
1 point

Select all statements that correctly describe configuration counts and meso compounds.

  1. A

    A molecule with n independent chirality centers has at most 2n2^n configurations.

  2. B

    Symmetry can reduce the number of distinct configurations.

  3. C

    A meso compound has stereogenic centers but is achiral overall because of molecular symmetry.

  4. D

    Every molecule with stereogenic centers must be chiral overall.

14
Open ended
1 point

Explain the steps for assigning an R or S descriptor to a stereogenic center, including how to handle the lowest-priority group if it points toward you.

15
Choose one
1 point

A butane molecule can adopt either an anti arrangement, with its methyl groups 180° apart, or a gauche arrangement, with them 60° apart. Which arrangement is more stable?

  1. A

    The gauche arrangement, because the methyl groups are closer together

  2. B

    The anti arrangement, because the methyl groups are farther apart

  3. C

    The two arrangements are equally stable because they differ only by rotation

  4. D

    Neither arrangement; only eclipsed conformations are stable

16
Written response
1 point

Which optical property of a compound cannot be inferred from its R or S descriptor alone?

17
Choose one
1 point

For an alkene, the higher-priority substituent on each double-bond carbon lies on the same side of the double bond. Which E/Z descriptor applies?

  1. A

    E, because the groups are on the same side

  2. B

    Z, because the groups are on opposite sides

  3. C

    Z, because the higher-priority groups are on the same side

  4. D

    E, because the higher-priority groups are on the same side

18
Choose one
1 point

Compare (2R,3R)-2,3-dibromobutane and (2R,3S)-2,3-dibromobutane. What is their stereochemical relationship?

  1. A

    They are enantiomers because both have two chirality centers

  2. B

    They are diastereomers because they differ at one center but not the other

  3. C

    They are conformers because one descriptor changes

  4. D

    They are identical because they share the same configuration at one center

19
Written response
1 point

Under CIP rules, when two directly attached atoms tie in atomic number, what is compared next to rank their groups?

20
Choose one
1 point

A pair of molecular arrangements cannot interconvert by free rotation around single bonds. Which description best distinguishes the arrangements?

  1. A

    A configuration, because it does not freely interconvert by rotation around single bonds

  2. B

    A conformation, because changing it always requires breaking a bond

  3. C

    A conformer, because it is a stereoisomer that cannot interconvert

  4. D

    An enantiomer, because all stereochemical changes require bond breaking