Question

Question #fc006

Answer 1

Test tube 1 contains the silver and so must be `"AgNO"_3`. The silver reacts with sulfide and iodide ions to give the precipitates so you should now see what is in test tubes 2 and 3.

Answer 2

Mix some of the silver nitrate solution with each of the other tubes to identify the iodide.......

Explanation:

Having identified the test tube containing the silver nitrate, add some of this to the contents of each of the other tubes. The one that yields a pale yellow precipitate will be the one containing the potassium iodide.

`KI (aq)` + `AgNO_3(aq)` --> `KNO_3 (aq)` + `AgI (s)`

The precipitate is silver iodide.