[easily]

I have  a salt with either sulfate or sulfite anion, and I'm supposed to find out which one it is and how it cant be anything else.

My salt responds perfectly to the sulfate anion test: HCl + salt (aq) + BaCl2 gives me a white precipitate.

However, when I add Heating+ HNO3 + salt (aq) and then later added AgNO3 to confirm that it's not sulfite or a halide, i get a white precipitate, meaning that it's supposed to be chloride. I heated it to make sure it's not sulfite, but the precipitate didn't go away; the solution turned from white to clear after rigorous shaking, but a white precipitate still floated on the top of the solution.

Now I'm kinda stuck and need help. Is sulfate supposed to do this? Does this mean it's sulfite? Or did I just contaminate my sample with a halide (I was testing for halides earlier but I did clean out everything), or did I do the heating wrong to get rid of the sulfite, or what?

Thanks

[chenbeier]

Sulfite decompose by adding acid. It smells of SO₂ gas. So there will be no precipitate.