Skip to main content
Ch.18 - Aqueous Ionic Equilibrium
Tro - Chemistry: A Molecular Approach 5th Edition
Tro5th EditionChemistry: A Molecular ApproachISBN: 9780134874371Not the one you use?Change textbook
All textbooksTro 5th EditionCh.18 - Aqueous Ionic EquilibriumProblem 29b
Chapter 18, Problem 29b

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. b. a solution that is 0.16 M in NH3 and 0.22 M in NH4Cl

Verified step by step guidance
1
Identify the equilibrium reaction: NH3 + H2O ⇌ NH4+ + OH−.
Write the expression for the base dissociation constant (Kb) for NH3: Kb = [NH4+][OH−] / [NH3].
Set up an ICE table (Initial, Change, Equilibrium) for the concentrations of NH3, NH4+, and OH−.
Use the initial concentrations: [NH3] = 0.16 M, [NH4+] = 0.22 M, and [OH−] = 0 M. Assume x is the change in concentration for NH4+ and OH−.
Substitute the equilibrium concentrations into the Kb expression and solve for x, which represents [OH−]. Then, calculate pOH and use it to find the pH.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
5m
Was this helpful?

Key Concepts

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

Equilibrium and ICE Tables

Equilibrium in chemistry refers to the state where the concentrations of reactants and products remain constant over time. An ICE table (Initial, Change, Equilibrium) is a tool used to organize the concentrations of species involved in a reaction at different stages. It helps in calculating the changes in concentration as the system reaches equilibrium, which is essential for solving equilibrium problems.
Recommended video:
Guided course
01:14
ICE Charts and Equilibrium Amount

Weak Bases and Conjugate Acids

Ammonia (NH3) is a weak base that partially ionizes in water to form hydroxide ions (OH-) and ammonium ions (NH4+). The presence of NH4Cl provides the conjugate acid (NH4+) of the weak base, which influences the pH of the solution. Understanding the relationship between weak bases and their conjugate acids is crucial for calculating the pH in buffer solutions.

Henderson-Hasselbalch Equation

The Henderson-Hasselbalch equation is a mathematical formula used to calculate the pH of buffer solutions. It relates the pH of a solution to the pKa of the weak acid and the ratio of the concentrations of the conjugate base and acid. In this case, it can be applied to find the pH of the solution containing NH3 and NH4Cl, providing a quick way to determine the pH without extensive calculations.
Recommended video:
Guided course
02:40
Henderson-Hasselbalch Equation
Related Practice
Textbook Question

In which of these solutions will HNO2 ionize less than it does in pure water? a. 0.10 M NaCl b. 0.10 M KNO3 c. 0.10 M NaOH d. 0.10 M NaNO2

2308
views
Textbook Question

A formic acid solution has a pH of 3.25. Which of these substances will raise the pH of the solution upon addition? Explain your answer. a. HCl b. NaBr c. NaCHO2 d. KCl

2806
views
1
rank
Textbook Question

Calculate the percent ionization of a 0.15 M benzoic acid solution in pure water and in a solution containing 0.10 M sodium benzoate. Why does the percent ionization differ significantly in the two solutions?

1979
views
Textbook Question

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. a. 0.15 M HF

1231
views
Textbook Question

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. b. 0.15 M NaF

508
views