Calculate the pH and the percent dissociation of the hydrated cation in the following solutions. See Appendix C for the value of the equilibrium constant. (a) 0.010 M Cr1NO323

검증된 단계별 안내

Identify the hydrated cation in the solution. For Cr(NO_3)_3, the hydrated cation is Cr^{3+}.

Write the equilibrium expression for the hydrolysis of Cr^{3+} in water: Cr^{3+} + 3H_2O \(\rightleftharpoons\) Cr(OH)_3 + 3H^+.

Use the equilibrium constant (K_eq) for the hydrolysis reaction from Appendix C to set up the expression: K_eq = [Cr(OH)_3][H^+]^3 / [Cr^{3+}].

Assume that the initial concentration of Cr^{3+} is 0.010 M and that the change in concentration due to hydrolysis is x. Set up the equilibrium concentrations: [Cr^{3+}] = 0.010 - x, [H^+] = 3x, and [Cr(OH)_3] = x.

Substitute the equilibrium concentrations into the K_eq expression and solve for x, which represents the concentration of H^+ ions. Use this to calculate the pH as pH = -\(\log\)[H^+].

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

10m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

pH Calculation

pH is a measure of the acidity or basicity of a solution, defined as the negative logarithm of the hydrogen ion concentration. To calculate pH, one must first determine the concentration of hydrogen ions in the solution, which can be derived from the dissociation of acids or bases. For weak acids, the pH can be calculated using the equilibrium expression involving the acid dissociation constant (Ka).

Percent Dissociation

Percent dissociation refers to the fraction of a solute that has dissociated into ions in a solution, expressed as a percentage. It is calculated by taking the concentration of dissociated ions at equilibrium, dividing it by the initial concentration of the solute, and multiplying by 100. This concept is particularly important for weak acids and bases, as it indicates the strength of the acid or base in solution.

Equilibrium Constant (K)

The equilibrium constant (K) quantifies the ratio of the concentrations of products to reactants at equilibrium for a given reaction. For acid-base reactions, the equilibrium constant is often represented as Ka for acids and Kb for bases. These constants are crucial for calculating pH and percent dissociation, as they provide the necessary information about the extent of dissociation of the solute in solution.