In the laboratory, you are given an unknown solution containing only three ions. You use the following qualitative analysis scheme: First, to a test tube labeled #1 containing all three ions, you add 6 M HCl and a precipitate forms. Next, you decant the remaining solution into a clean test tube labeled #2, and then add H2S and 0.2 M HCl and a precipitate forms. Finally, you decant the remaining solution into a clean test tube labeled #3 and add (NH4)2S at pH 8 and a precipitate forms. Which of the following lists three ions that could have been in your unknown solution? a. Ag+, Mg2+, and K+
b. Ag+, Cu2+, and Ca2+
c. Ag+, Cu2+, and Na+
d. Ag+, Cu2+, and Fe3+