You have one test tube which contains a colorless solution that is either cu+2 (aq) or bi+3(aq). select a reagent that will allow you to differentiate between the two chemical species. if the solution is cu+2, what will happen when the reagent is added? if the solution is bi+3, what will happen when the reagent is added?

Explanation:

You can use KI and K4[Fe(CN)6].

When you add KI in a solution with only Cu2+ nothing will happen, but when you add K4[Fe(CN)6] it will form a solid of Cu2[Fe(CN)6] that will be reddish-brown.

When you add K4[Fe(CN)6] in a solution with only Bi3+ nothing will happen, but when you add KI it will form a solid of BiI3 that will be black.

So in a solution which contains both of then, you can add KI to determinate Bi3+, if you see a black solid. If nothing happens, you can affirme that it contains Cu2+.

i believe the answer is a.