Correção de Exercícios - Lei de diluição de Ostwald

Theory, commented exercises and free teaching material without registration (https://bit.ly/equilibrioionico) Answer key for the exercises 8. Uerj mock exam 2018 - B (00:00) 9. ITA-SP - C (02:10) 10. UFES-ES - 4.1% (04:15) 11. FUVEST-SP - B (05:45) Theory of the content:    • Lei de diluição de Ostwald   Instagram:   / gehideo   Exercises 8. (Uerj mock exam 2018) Hydrogen cyanide (HCN) is an extremely toxic gas that ionizes when dissolved in water, according to the reaction below. HCN⁻(aq) ⇄ H⁺(aq) + CN⁻ In an experiment, an aqueous solution was prepared with a concentration of 0.1 mol⋅L⁻¹ and a degree of ionization equal to 0.5%. The concentration of cyanide ions in this solution, in mol⁻¹, is equal to: a) 2.5 × 10⁻⁴ b) 5.0 × 10⁻⁴ c) 2.5 × 10⁻² d) 5.0 × 10⁻² 9 (ITA-SP) In a 0.100 mol/L aqueous solution of a monocarboxylic acid, at 25 °C, the acid is 3.7% ionized after equilibrium has been reached. Indicate the option that contains the correct value of the ionization constant of this acid at this temperature. a) 1.4 b) 1.4 · 10⁻³ c) 1.4 · 10⁻⁴ d) 3.7 · 10⁻² e) 3.7 · 10⁻⁴ 10 (UFES-ES) A solution is prepared by introducing 14.1 g of nitrous acid (HNO₂) into a 1000 cm³ volumetric flask and completing it with distilled water. Knowing that 4.1% of the acid ionized, determine the values ​​of the concentrations of the products at equilibrium and the value of Ka for nitrous acid. Data: Atomic masses H = 1 u, N = 14 u, O = 16 u 11 (FUVEST-SP) Numerical value of the ionization constant of acetic acid = 1.8 · 10⁻⁵. A given sample of vinegar was diluted with water until a solution with [H+] = 10⁻³ mol/L was obtained. In this solution, the concentrations, in mol/L, of CH₃COO⁻ and CH₃COOH are, respectively, on the order of: a) 3 · 10⁻¹ and 5 · 10⁻¹⁰ b) 3 · 10⁻¹ and 5 · 10⁻² c) 1 · 10⁻³ and 2 · 10⁻⁵ d) 1 · 10⁻³ and 5 · 10⁻¹² e) 1 · 10⁻³ and 5 · 10⁻²