[ryguy1410]

Got a tricky problem that I encountered in lab today, and was hoping that I could get some help. I received a simple salt that appeared white-yellow solid that is insoluble in H20, HNO3, and NH3. It is soluble in HCl and NaOH. The solution when dissolved is clear, so that narrowed down my cations to Sn, Sb, Al, Zn, Ag, Pb, Bi. I tested Ag and Pb, but found that it was not in the solid. Then I dissolved the solid in thioacetamide which resulted in a distinct yellow precipitate. The lab book says this is Sn, so I decided to check it. I received a positive confirmation of the cation being tin upon testing.

Then the anions. I tested PO4(3-) and did not get a positive test, and then decided to check the sulfates. The test is done by checking first for sulfate, and if you receive confirmation you do another test for sulfite (SO3(2-)). I got a positive test for the sulfate, but not for the sulfite. The problem is that my book says that my salt would be soluble in H20 if I had a salt with SnSO4.

My questions are 1) Is there anything tricky about the SnSO4 combination that could cause these results?

2) Given the list above, what other sulfides could possibly precipitate with those cations to produce such a bright yellow ppt?

3) If my salt is this, should be be more aggressive with dissolving it in H20, such as maybe I didn't add enough when evaluating it the first time?