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

1. A Review of General Chemistry

Constitutional Isomers

Organic Chemistry

1. A Review of General Chemistry

Constitutional Isomers

Previous problemNext problem

Problem 2

Textbook Question

Determine the number of elements of unsaturation in the molecular formula C₄H₆. Give all nine possible structures having this formula. Remember that
a double bond = one element of unsaturation
a ring = one element of unsaturation
a triple bond = two elements of unsaturation

Verified step by step guidance

Step 1: Calculate the degree of unsaturation using the formula: Degree of Unsaturation = (2C + 2 + N - H) / 2, where C is the number of carbons, N is the number of nitrogens, and H is the number of hydrogens.

Step 2: Substitute the values from the molecular formula C4H9N into the formula: Degree of Unsaturation = (2(4) + 2 + 1 - 9) / 2.

Step 3: Simplify the expression to find the degree of unsaturation. This will tell you how many rings and/or multiple bonds are present in the molecule.

Step 4: Use the degree of unsaturation to determine possible structures. Consider combinations of rings, double bonds, and triple bonds that match the degree of unsaturation.

Step 5: Draw all possible structures that fit the molecular formula C4H9N and the calculated degree of unsaturation. Ensure that each structure adheres to the rules of valency for carbon and nitrogen.

Verified video answer for a similar problem:

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

Play a video:

Was this helpful?

Key Concepts

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

Elements of Unsaturation

Elements of unsaturation, also known as degrees of unsaturation, indicate the number of rings and multiple bonds (double or triple) in a molecule. Each double bond or ring counts as one element of unsaturation, while a triple bond counts as two. This concept helps in determining the possible structures of a molecule from its molecular formula.

Molecular Formula Analysis

Analyzing a molecular formula involves calculating the elements of unsaturation to predict possible structures. For a given formula, the degrees of unsaturation can be calculated using the formula: (2C + 2 + N - H)/2, where C, N, and H are the number of carbon, nitrogen, and hydrogen atoms, respectively. This calculation helps in identifying the presence of rings or multiple bonds.

Structural Isomerism

Structural isomerism occurs when molecules with the same molecular formula have different connectivity of atoms. In the context of C4H9N, structural isomers can include variations in the arrangement of carbon chains, the position of nitrogen, and the presence of rings or multiple bonds. Understanding isomerism is crucial for enumerating all possible structures for a given formula.

Watch next

Master What is a constitutional isomer? with a bite sized video explanation from Johnny

Start learning