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

3. Acids and Bases

Equilibrium Constant

Organic Chemistry

3. Acids and Bases

Equilibrium Constant

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5:22 minutes

Problem 5b

Textbook Question

Calculate K_eq for the following acid–base reactions.
(b)

Verified step by step guidance

Step 1: Identify the acid and base on both sides of the reaction. Determine which species is donating a proton (acid) and which is accepting a proton (base).

Step 2: Look up the pKa values of the acids on both sides of the reaction. The pKa value indicates the strength of an acid; lower pKa values correspond to stronger acids.

Step 3: Use the relationship between pKa and equilibrium constant (Kₑq). The formula is:

K_{eq} = 10^{(p_{K a (acid) - p_{K a (conjugate acid))}}}

Step 4: Subtract the pKa of the conjugate acid from the pKa of the acid to find the exponent for the equilibrium constant calculation.

Step 5: Express the equilibrium constant (Kₑq) as a power of 10 using the calculated exponent. This will give you the relative favorability of the reaction.

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Key Concepts

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

Acid-Base Reactions

Acid-base reactions involve the transfer of protons (H⁺ ions) between reactants. In these reactions, acids donate protons while bases accept them. Understanding the nature of the acids and bases involved is crucial for predicting the direction of the reaction and calculating equilibrium constants.

Equilibrium Constant (Kₑq)

The equilibrium constant (Kₑq) quantifies the ratio of the concentrations of products to reactants at equilibrium for a given reaction. For acid-base reactions, Kₑq can be derived from the concentrations of the conjugate acids and bases involved. It provides insight into the strength of the acids and bases and the favorability of the reaction.

Conjugate Acid-Base Pairs

Conjugate acid-base pairs consist of an acid and its corresponding base that differ by a single proton. When an acid donates a proton, it forms its conjugate base, and vice versa. Recognizing these pairs is essential for calculating Kₑq, as it helps in determining the relative strengths of the acids and bases in the reaction.