Question

1. A complex, [CuCl 5.0x10 forms when mixing aqueous solutions of CuCla and NaCl. The Kr for this reaction is a. Write the balanced equation for this equilibrium reaction. b. If Na:CO3 is added to the solution, a precipitate will form. Identify the precipitate. c. The Kap for this precipitate is 2.5x1010, What is the value of the equilibrium constant governing the equilibrium from part b? 2. For the following salt: KF a. Write the chemical equation for the anion (base) hydrolysis. b. What is the weak acid or weak base produced when the salt hydrolyzes? If no weak acid or base results fror the hydrolysis, say "none" c. Is the solution acidic, basic, neutral or you can't tell? Briefly explain.

Answer 1

Q1:

(a) Cu²⁺(aq) + 4 Cl^- $\leftrightharpoons$ [CuCl₄]^2-

(b) CuCO₃ precipitate will form .

(c)

[CuCl₄]^2- + CO₃^2- $\leftrightharpoons$ CuCO₃ + 4 Cl^- K = (1/K_f)×(1/K_sp) = 1/(2.5×10^-10×5×10⁵) = 10⁵/12.5 = 8.0×10³

Q2:

(a) F^-(aq) + H₂O $\leftrightharpoons$ HF + OH^-

(b) weak acid HF is produced .

(c) the solution would be basic .

Because KF is a salt of strong base and weak acid, anionic hydrolysis would releases OH^- ions .