An ionic solution is investigated for identity. Using the following clues, identify the cation and the anion in the solution:

a. There is only one cation and one anion in the solution

b. The solution is clear

c. The anion is either nitrate, iodide, or chloride

d. The solution reacts with Copper (II) ions forming a precipitate of copper

e. The solution reacts with hydrochloric acid, forming a brown gas

f. The solution won't react with nickel ions, but it will react with nickel metal and every other metal below nickel