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−.
2. Write the expression for the base dissociation constant (Kb) for NH3: Kb = [NH4+][OH−] / [NH3].
3. Set up an ICE table (Initial, Change, Equilibrium) for the concentrations of NH3, NH4+, and OH−.
4. 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−.
5. 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.

Key Concepts

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.

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.