Consider the exothermic equilibrium system below.
The [CuCl4]–2(aq) ion is light green while the [CuBr4]2(aq) ion is dark brown. Originally the equilibrium below was a dark green.

[CuCl4]–2(aq) + 4 Br–(aq) ⇋ [CuBr4]–2(aq) + 4 Cl–(aq)

Predict the color of the solution after the system has re-established equilibrium.

a. Adding a small amount of white NaBr(s).
b. Adding a few drops of Ag+(aq) solution (Ag+ reacts with Cl– ions).

Can someone explain this to me please and show me how you got the answer?