Test For Anions

Question 1

How can you test for carbonates

Answer 1

Use dilute hydrochloric acid

If CO3 (2-) present carbon dioxide released

CO3 (2-) + 2H+ = CO2 + H2O

Test CO2 with limewater

Question 2

How do you test for sulfates (SO4) (2-)

Answer 2

Produce white precipitate with HCL to get rid of carbonate or sulfite ions so they dont also produce precipitates

Then add Barium Chloride BaCl2

ba2+ + SO4 2- = BaSO4

Question 3

Test for halides Cl- Br- I-

Answer 3

Add nitric acid to get rid of carbonate and sulfide ions as they can produce precipitates

Then add silver nitrate solution AgNO3

Chloride reacts with silver to form white precipitate

Bromide cream silver bromide

Iodide yellow silver iodide