•Soluble Ionic Compounds:
▪ Group 1A ions (Li+, Na+, K+, etc.) and Ammonium ion (NH4+) are soluble
▪ Nitrates (NO3-), Acetates (CH3COO- or C2H3O2-), and most Perchlorates (ClO4-) are soluble
▪ Cl-, Br-, and I- are soluble except when paired with Ag+, Pb2+, Cu+, Hg22+
▪ Sulfates (SO42-) are soluble except those of Ca2+, Sr2+, Ba2+, Ag+, and Pb2+
• Insoluble Ionic Compounds:
A student was given a solid containing a mixture of nitrate salts. The sample completely dissolved in water, and upon addition of dilute HCl, no precipitate formed. The pH was lowered to about 1 and H2S was bubbled through the solution. No precipitate formed. The pH was adjusted to 8 and H2S was again bubbled in. This time, a precipitate formed.
Which compounds might have been present in the unknown?