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

6. Thermodynamics and Kinetics

Entropy

Organic Chemistry

6. Thermodynamics and Kinetics

Entropy

Previous problemNext problem

1:07 minutes

Problem 17

Textbook Question

Estimate the value of entropy (∆S > 0 or ∆S < 0) for the elimination step shown.

Verified step by step guidance

Step 1: Understand the concept of entropy (∆S). Entropy is a measure of disorder or randomness in a system. In chemical reactions, ∆S > 0 indicates an increase in disorder, while ∆S < 0 indicates a decrease in disorder.

Step 2: Analyze the elimination reaction. Elimination reactions typically involve the removal of atoms or groups from a molecule, resulting in the formation of a double bond and often the release of smaller molecules like H₂O or HCl.

Step 3: Consider the molecular changes during the elimination step. The reactant is usually a single, larger molecule, and the products are typically a smaller molecule (e.g., H₂O or HCl) and an unsaturated molecule (e.g., an alkene). This change generally increases the number of particles in the system.

Step 4: Evaluate the impact on entropy. The increase in the number of particles and the formation of a more disordered gaseous or liquid product typically leads to an increase in entropy (∆S > 0).

Step 5: Conclude based on the analysis. For elimination reactions, the entropy change is usually positive (∆S > 0) due to the increase in disorder and the number of particles in the system.

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.

Entropy (S)

Entropy is a measure of the disorder or randomness in a system. In thermodynamics, it quantifies the number of possible arrangements of particles in a system. A positive change in entropy (∆S > 0) indicates an increase in disorder, while a negative change (∆S < 0) suggests a decrease in disorder. Understanding entropy is crucial for predicting the spontaneity of reactions.

Elimination Reactions

Elimination reactions are a type of organic reaction where two substituents are removed from a molecule, resulting in the formation of a double bond or a ring structure. These reactions often involve the loss of small molecules, such as water or hydrogen halides. The nature of the elimination process can significantly influence the entropy change, as the formation of gaseous products typically increases disorder.

Thermodynamic Favorability

Thermodynamic favorability refers to the likelihood of a reaction occurring based on changes in enthalpy (∆H) and entropy (∆S). A reaction is considered thermodynamically favorable if the Gibbs free energy change (∆G) is negative, which can occur when the increase in entropy compensates for any unfavorable enthalpic changes. Evaluating the entropy change during the elimination step is essential for determining the overall favorability of the reaction.

Watch next

Master Explaining what entropy is. with a bite sized video explanation from Johnny

Start learning

Related Videos

Related Practice

Textbook Question

The hydrogenation of alkenes is a reaction we study in Chapter 9.

(b) Is this reaction favored or disfavored in terms of entropy?

Textbook Question

Through the course of this chapter, we have discussed only alkane chlorination and bromination, yet there are two other halogens we have not discussed.

(b) Is radical iodination a favorable reaction? Do you expect it to be selective? Show your calculations.

Textbook Question

The dehydrogenation of butane to trans-but-2-ene has ΔH° = +116 kJ/mol (+27.6 kcal/mol) and ΔS° = +117J/kelvin-mol (+28.0 cal/kelvin-mol). a. Compute the value of ΔG° for dehydrogenation at room temperature (25 °C or 298 °K). Is dehydrogenation favored or disfavored?HINT: When you are doing synthesis problems, avoid using these high-temperature industrial methods. They require specialized equipment, and they produce variable mixtures of products.

Textbook Question

The dehydrogenation of butane to trans-but-2-ene has ΔH° = +116 kJ/mol (+27.6 kcal/mol) and ΔS° = +117J/kelvin-mol (+28.0 cal/kelvin-mol).

a. Compute the value of ΔG° for dehydrogenation at room temperature (25 °C or 298 °K). Is dehydrogenation favored or disfavored?

HINT: When you are doing synthesis problems, avoid using these high-temperature industrial methods. They require specialized equipment, and they produce variable mixtures of products.

Textbook Question

Would you expect ∆S to be greater than, less than, or equal to zero in the following reactions?

(b)

Textbook Question

For each of the following processes, indicate whether you expect ∆S° to be greater than, less than, or equal to 0. Explain your answer.

(d)

Textbook Question

For each of the following processes, indicate whether you expect ∆S° to be greater than, less than, or equal to 0. Explain your answer.

(c)

Textbook Question

For each of the following processes, indicate whether you expect ∆S° to be greater than, less than, or equal to 0. Explain your answer.

(b) 2 C₆H₁₄(l) + 19 O₂(g) → 12 CO₂(g) + 14 H₂O(g)

Show more practices

Download the Mobile app

Privacy

Do not sell my personal information

Accessibility

Patent notice

Sitemap