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Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics
Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
All textbooksMullins 1st EditionCh. 5 - Chemical Reaction Analysis: Thermodynamics and KineticsProblem 48a(i)
Chapter 4, Problem 48a(i)

For each of the following acid–base reactions, (i) predict which side of the reaction you expect to be favored. If a pKa is not one of the ten common ones we learned in Chapter 4, it will be given to you.
(a) Chemical reaction diagram showing hydroxide ion reacting with sulfuric acid to form hydronium and bisulfate ions.

Verified step by step guidance
1
Step 1: Identify the acid and base on both sides of the reaction. Acids donate protons (H⁺), while bases accept protons. Look at the reactants and products to determine which species are acting as acids and bases.
Step 2: Determine 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: Compare the pKₐ values of the acids. The equilibrium of the reaction will favor the side with the weaker acid (higher pKₐ value), as weaker acids are less likely to donate protons.
Step 4: Write the equilibrium expression for the reaction. Use the principle that equilibrium favors the formation of the weaker acid and weaker base.
Step 5: Predict the favored side of the reaction based on the comparison of pKₐ values. Clearly indicate whether the reactants or products are favored in equilibrium.

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Key Concepts

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

Acid-Base Theory

Acid-base theory explains the behavior of acids and bases in chemical reactions. According to the Brønsted-Lowry theory, acids are proton donors while bases are proton acceptors. Understanding this concept is crucial for predicting the direction of acid-base reactions, as the equilibrium will favor the formation of the weaker acid and base.
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The Lewis definition of acids and bases.

pKₐ and its Significance

pKₐ is a quantitative measure of the strength of an acid in solution, defined as the negative logarithm of the acid dissociation constant (Kₐ). A lower pKₐ value indicates a stronger acid, which dissociates more completely in solution. In acid-base reactions, comparing the pKₐ values of the acids involved helps predict which side of the reaction is favored, as the equilibrium will shift towards the weaker acid.
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Equilibrium in Acid-Base Reactions

In acid-base reactions, equilibrium refers to the state where the rates of the forward and reverse reactions are equal. The position of equilibrium can be influenced by the relative strengths of the acids and bases involved. By applying Le Chatelier's principle, one can predict how changes in concentration or conditions will affect the equilibrium position, thus determining which side of the reaction is favored.
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Related Practice
Textbook Question

Predict the major monohalogenation product(s) of the following reactions. Indicate whether you think the reaction will be selective and justify your position.

(c)

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Textbook Question

The following table of strain energies is associated with a variety of 1,2-gauche interactions. Use this table to answer the questions (i)–(iv).

For each of the bond rotations shown, (i) identify which you believe to be more stable, (ii) calculate ∆G°, (iii) calculate the equilibrium constant, and (iv) draw the transition state.

(c)

5
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Textbook Question

For each of the following acid–base reactions, (iv) draw the transition state, paying close attention to the degree of bond forming and breaking present in the transition state. If a pKa is not one of the ten common ones we learned in Chapter 4, it will be given to you.

(a)

Textbook Question

For each of the following acid–base reactions, (ii) calculate Keq. If a pKa is not one of the ten common ones we learned in Chapter 4, it will be given to you.

(a)

2
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Textbook Question

For each of the following acid–base reactions, (iii) calculate ∆G°. If a pKa is not one of the ten common ones we learned in Chapter 4, it will be given to you.

(a)

5
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Textbook Question

Predict the major monohalogenation product(s) of the following reactions. Indicate whether you think the reaction will be selective and justify your position.

(a)

1
views