Testing for anions (other than halides)

Question 1

Sulfate

Answer 1

step 1) add hydrocholoric acid (can use nitric acid) to remove possible carbonate impurities
step 2) add Barium Chloride solution
step 3) if sulfate ions are present a white precipitate will form.
SO4^2-(aq) + Ba^2+(aq) -> BaSO4(s)
white ppt (precipitate); Barium sulphate

Question 2

Carbonate

Answer 2

step 1) add hydrochloric acid
step 2) collect the gas and test with limewater, if it turns cloudy then carbonate ions are present
CO3^2-(aq) + 2H^+ (aq) -> CO2(s) + H2O(l)