Problem on concentrations and solutions

Question

Assignment:

Question 1. The Equilibrium constant Kp for the reaction

2SO2(g) + O2(g) ß---à 2SO3(g)

Is 5.60 x 10^4 at 350 degrees C. The initial pressures of SO2 is 0.350 atm and the initial pressure of O2 is 0.762 atm at 350 degrees C. When a mixture equillibtrates, is the total pressure less than or greater than the sum of the initial pressures (1.112 atm)?

Question 2. You are working as a lab assistant and are tasked to prepare an acetic acid - sodium acetate buffer solution with a pH of 4.00 ± 0.02. What molar ratio of CH₃COOH to CH₃COONa should be used?

Question 3. The equilibrium constant Kc for the reaction

H2(g) + Br(g)  ß-----à 2HBr(g)

Is 2.18 x 10^6 at 730 degrees C. Starting with 3.20 moles of HBr in a 12.0-L reaction vessel, calculate the concentrations of H2, Br2, and HBR at equilibrium.

Question 4. Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 4.6 - 4.8?

1. CH₃COO₂Na / CH₃COOH (K_a = 1.8 x 10^-5)
2. NH₃ / NH₄Cl (K_a(NH₄⁺) = 5.6 x 10^-10)
3. NaOCl / HOCl (K_a = 3.2 x 10^-8)
4. NaNO₂ / HNO₂ (K_a = 4.5 x 10^-4)
5. NaCl / HCl

Question 5. You have 500.0 mL of a buffer solution containing 0.20 M acetic acid (CH₃COOH) and 0.30 M sodium acetate (CH₃COONa). What will the pH of this solution be after the addition of 20.0 mL of 1.00 M NaOH solution?

K_a = 1.8 x 10^-5

Question 6. 50.00 mL of 0.10 M HNO₂ (nitrous acid) was titrated with 0.10 M KOH solution. After 25.00 mL of KOH solution was added, what was the pH in the titration flask? (Given K_a = 4.5 x 10^-4)

Question 7. The solubility product for CrF₃ is K_sp = 6.6 x 10^-11. What is the molar solubility of CrF₃?

Question 8. The K_sp for Ag₃PO₄ is 1.8 x 10^-18. Determine the Ag⁺ ion concentration in a saturated solution of Ag₃PO₄.

Question 9. Will a precipitate of MgF₂ form when 300 mL of 1.1 x 10^-3 M MgCl₂ solution are added to 500 mL of 1.2 x 10^-3 M NaF? K_sp (MgF₂) = 6.9 x 10^-9