A student was given a sample of a colourless solution containing three cations and was asked to identify the cations. The student carried out a series of reactions as shown in the flow chart below:
From the information above, suggest three cations which could be in the sample and would form the precipitates A, B and C. Give the formula for each precipitate.
The Attempt at a Solution
I think that precipitate A is AgCl because AgCl is insoluble. This means one of the cations is Ag+. However, I am stuck and don't really know how to move on. In the second step, Na2SO4 solution is added to the AgCl. I am not sure what precipitate will be formed. I am guessing that it has something to do with the other cations but I don't really know. I am pretty sure I have misinterpreted the question so could some please explain where I went wrong?