Second question: Given the Chemical Recation:

Cu+2(aq) + 2Cl-1(aq) --> CuCl2 (s)

Which of the following statements best defines the common ion effect?
A. When a chemical reaction has reached equilibrium and we add more of one of the ions that already exists in the solution, the forward reaction will proceed at a faster rate, and the equilibrium will be reestablished.
B. When a chemical reaction has reached equilibrium and we add more of one of the ions that already exists in the solution, the reverse reaction will proceed at a slower rate, and the equilibrium will be reestablished.
C. When a chemical reaction has reached equilibrium and we add more of one of the ions that already exists in the solution, the reverse reaction will proceed at a faster rate, and the equilibrium will not be reestablished.
D. When a chemical reaction has reached equilibrium and we add more of one of the ions that already exists in the solution, the reverse reaction will proceed at a faster rate, and the equilibrium will be reestablished.

I think the correct answer would be D. Base from the common ion effect, when a chemical reaction has reached equilibrium and we add more of one of the ions that already exists in the solution, the reverse reaction will proceed at a faster rate, and the equilibrium will be reestablished. Adding a common ion would decrease solubility and would lead to the dissociation of the products.

Answer Link