chemistry- anions and anion tests

nitrate

NO₃⁻

Hydrogen carbonate

HCO₃⁻

Sulfate

SO₄²⁻

Sulfite

SO₃²⁻

Thiosulfate

S₂O₃²⁻

Carbonate

CO₃²⁻

Phosphate

PO₄³⁻

Chloride

Cl⁻

Test for chloride ions- materials

soluble chloride salt e.g. NaCl, silver nitrate solution (0.1M), dilute ammonia solution (3M)

Chloride test- results

clear solution turns cloudy, white precipitate formed (silver chloride), disappears when ammonia solution added

test for sulfate and sulfite ions- materials

soluble sulfate salt e.g. Na2SO4, soluble sulfite salt, e.g. Na2SO3, barium chloride solution, dilute HCl

sulfate and sulfite test- results

clear solution turns cloudy, white precipitate forms (barium sulfate/sulfite). HCl added- cloudiness disappears in sulfite solution, remains in sulfate

carbonate and hydrogencarbonate test- materials

soluble carbonate salt, e.g. Na2CO3, soluble hydrogencarbonate salt e.g. NaHCO3, dilute HCl, limewater, magnesium sulfate solution

carbonate and hydrogencarbonate test- results

effervescence occurs, limewater turns milky (CO2 produced). magnesium sulfate added- precipitate forms in carbonate solution, not in hydrogen carbonate

test for nitrate ions- materials

nitrate salt e.g. NaNO3, iron sulfate solution, concentrated sulfuric acid

nitrate test- results

brown ring forms where nitrate and iron sulfate solution meet sulfuric acid

test for phosphate ions- materials

soluble phosphate salt, e.g. Na2HPO4, ammonium molybdate solution, concentrated nitric acid

phosphate test- results

yellow precipitate is formed- ammonium phosphomolybdate