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

Cis vs Trans

Organic Chemistry

4. Alkanes and Cycloalkanes

Cis vs Trans

Previous problemNext problem

2:58 minutes

Problem 8a

Textbook Question

Assign relative priorities to each set of substituents:
a. -Br, -I, -OH, -CH₃

Verified step by step guidance

Step 1: Understand the Cahn-Ingold-Prelog (CIP) priority rules. These rules are used to assign priorities to substituents based on atomic number, isotopic mass, and connectivity. The higher the atomic number, the higher the priority.

Step 2: Compare the atomic numbers of the atoms directly attached to the carbon. For the given substituents: -Br (atomic number 35), -I (atomic number 53), -OH (oxygen has atomic number 8), and -CH3 (carbon has atomic number 6). Assign priorities based on these atomic numbers.

Step 3: Assign the highest priority to the substituent with the highest atomic number. In this case, iodine (-I) has the highest atomic number (53), so it gets the highest priority.

Step 4: Assign the second highest priority to bromine (-Br), as it has the next highest atomic number (35). Oxygen (-OH) comes next with an atomic number of 8, followed by carbon (-CH3) with an atomic number of 6.

Step 5: Finalize the relative priorities as follows: 1) -I, 2) -Br, 3) -OH, 4) -CH3. These priorities will be used in stereochemical assignments such as R/S configuration or E/Z isomerism.

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.

Substituent Effects

Substituent effects refer to how different groups attached to a carbon chain influence the reactivity and stability of organic molecules. These effects can be electronic, such as electron-donating or electron-withdrawing properties, or steric, which involves the physical size and spatial arrangement of the substituents. Understanding these effects is crucial for predicting the behavior of molecules in reactions.

Priority Rules in Organic Chemistry

In organic chemistry, priority rules are used to determine the order of substituents based on their atomic number and connectivity. The Cahn-Ingold-Prelog (CIP) priority rules are commonly applied to assign priorities, where higher atomic numbers take precedence. This is essential for understanding stereochemistry and reactivity in substitution reactions.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In the context of the question, -Br (bromine), -I (iodine), -OH (hydroxyl), and -CH3 (methyl) are all functional groups with distinct properties. Recognizing these groups helps in assigning relative priorities based on their reactivity and influence on the molecular structure.

Watch next

Master How to name different types of double bonds or rings with a bite sized video explanation from Johnny

Start learning