Domanda del libro di testo
Identify each substance as an acid or a base and write a chemical equation showing how it is an acid or a base according to the Arrhenius definition. a. HNO3(aq) b. NH4+(aq) d. HC2H3O2(aq)
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Ch.16 - Acids and Bases
Tro4th EditionChemistry: A Molecular ApproachISBN: 9780134112831
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TOC.tableOfContents
- Ch.1 - Matter, Measurement & Problem Solving136
- Ch.2 - Atoms & Elements112
- Ch.3 - Molecules, Compounds & Chemical Equations159
- Ch.4 - Chemical Quantities & Aqueous Reactions140
- Ch.5 - Gases118
- Ch.6 - Thermochemistry106
- Ch.7 - Quantum-Mechanical Model of the Atom62
- Ch.8 - Periodic Properties of the Elements103
- Ch.9 - Chemical Bonding I: The Lewis Model104
- Ch.10 - Chemical Bonding II: Molecular Shapes & Valence Bond Theory89
- Ch.11 - Liquids, Solids & Intermolecular Forces73
- Ch.12 - Solids and Modern Material59
- Ch.13 - Solutions110
- Ch.14 - Chemical Kinetics140
- Ch.15 - Chemical Equilibrium78
- Ch.16 - Acids and Bases155
- Ch.17 - Aqueous Ionic Equilibrium176
- Ch.18 - Free Energy and Thermodynamics108
- Ch.19 - Electrochemistry118
- Ch.20 - Radioactivity and Nuclear Chemistry82
- Ch.21 - Organic Chemistry150
Tro4th EditionChemistry: A Molecular ApproachISBN: 9780134112831Non è quello che usi tu?Cambia libro di testo
Capitolo 16, Problema 7
A 0.115 M solution of a weak acid (HA) has a pH of 3.29. Calculate the acid ionization constant (Ka) for the acid.
Guida verificata passo dopo passo1
Step 1: Understand the problem. We are given the concentration of a weak acid (HA) and the pH of the solution. We need to find the acid ionization constant (K_a).
Step 2: Convert the pH to the concentration of hydrogen ions [H^+]. Use the formula: [H^+] = 10^{-pH}.
Step 3: Write the expression for the ionization of the weak acid: HA \(\rightleftharpoons\) H^+ + A^-.
Step 4: Set up the expression for the acid ionization constant (K_a): K_a = \(\frac{[H^+][A^-]}{[HA]}\).
Step 5: Assume that [H^+] = [A^-] and that the initial concentration of HA decreases by [H^+]. Substitute these values into the K_a expression and solve for K_a.
Concetti chiave
Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.
pH and pKa
pH is a measure of the hydrogen ion concentration in a solution, calculated as pH = -log[H+]. For weak acids, the pKa is related to the strength of the acid, with lower pKa values indicating stronger acids. The relationship between pH and pKa is crucial for understanding acid dissociation and calculating the acid ionization constant (Ka).
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Percorso guidato
02:33
The pH Scale
Acid Ionization Constant (Ka)
The acid ionization constant (Ka) quantifies the strength of a weak acid in solution. It is defined by the equilibrium expression: Ka = [H+][A-]/[HA], where [H+] is the concentration of hydrogen ions, [A-] is the concentration of the conjugate base, and [HA] is the concentration of the undissociated acid. A higher Ka value indicates a stronger acid.
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Percorso guidato
03:50Characteristics of Ka and Kb
Equilibrium Concentrations
In a weak acid solution, the equilibrium concentrations of the species involved must be determined to calculate Ka. For a weak acid HA dissociating into H+ and A-, the initial concentration, the change in concentration due to dissociation, and the equilibrium concentrations are essential for applying the Ka expression. Understanding how to set up these concentrations is key to solving the problem.
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Percorso guidato
02:35Thermal Equilibrium