Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

4. Alkanes and Cycloalkanes

Newman Projections

Organic Chemistry

4. Alkanes and Cycloalkanes

Newman Projections

Previous problemNext problem

7:23 minutes

Problem 34f

Textbook Question

Which of the following structures represent the same compound? Which ones represent different compounds?
(f)

Verified step by step guidance

Step 1: Analyze the structures provided. Each structure represents a Newman projection, which is a way to visualize the conformation of a molecule by looking down a specific carbon-carbon bond.

Step 2: Identify the groups attached to the front and back carbons in each Newman projection. For example, in Structure 1, the front carbon has groups CH3, H, and CH2CH3, while the back carbon has CH3, H, and CH2CH3.

Step 3: Compare the groups and their relative positions in each structure. Two structures represent the same compound if the groups and their spatial arrangements (staggered or eclipsed) are identical after considering possible rotations around the carbon-carbon bond.

Step 4: Check for any differences in the groups or their arrangements. For example, Structure 4 has a CH(CH3)2 group, which is different from the CH2CH3 group in other structures, indicating it represents a different compound.

Step 5: Conclude which structures are identical and which are different based on the analysis. Structures with identical groups and arrangements represent the same compound, while those with different groups or arrangements represent different compounds.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Structural Isomers

Structural isomers are compounds that have the same molecular formula but differ in the connectivity of their atoms. This means that while they contain the same number of each type of atom, the way these atoms are arranged can lead to different compounds with distinct properties. Understanding structural isomers is crucial for determining whether the given structures represent the same or different compounds.

Cyclic Compounds

Cyclic compounds are organic molecules that contain a ring structure. In the context of the question, the presence of a cyclohexane ring is significant, as it can lead to various substituents being attached to the ring. Recognizing the nature of cyclic compounds helps in analyzing how different substituents can affect the identity of the compound and whether the structures shown are identical or not.

Stereochemistry

Stereochemistry refers to the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. In the case of cyclic compounds, stereochemistry can lead to different isomers, such as cis and trans forms, which can have different physical and chemical properties. Understanding stereochemistry is essential for determining if the structures in the question represent the same compound or different ones based on their 3D orientation.

Watch next

Master How sigma bond rotation is visualized with a bite sized video explanation from Johnny

Start learning

Related Videos

Related Practice

Textbook Question

Construct a graph, similar to Figure 3-11, of the torsional energy of 3-methylpentane along the C2―C3 bond.

e. Indicate which conformations are the most stable (lowest energy) and the least stable (highest energy).

Textbook Question

Why is it incorrect to say that the dihedral angle shown is 120° or even 109°?

Textbook Question

For each pair of conformations shown, choose which is most stable. [If both conformations have the same number of gauche interactions, choose the one where the interactions are between smaller groups.]

(e)

Textbook Question

(f)

Textbook Question

Construct a graph, similar to Figure 3-11, of the torsional energy of 3-methylpentane along the C2―C3 bond.

a. Place C2 in front, represented by three bonds coming together in a Y shape, and C3 in back, represented by a circle with three bonds pointing out from it.

b. Define the dihedral angle as the angle between the methyl group on the front carbon and the ethyl group on the back carbon.

Textbook Question

Calculate the dihedral angle (θ) for the conformations shown.

(c)

Multiple Choice

What is the dihedral angle between two gauche groups in a Newman projection?

Textbook Question

Which of the following conformers of isobutyl chloride is the most stable?

Show more practices