Summary Of Tests For Anions Flashcards
What is the anion test for chloride ions?
Add a few drops of AgNO3 solution to a solution of the solid.
What observations are made for the test for chloride ions? Give the formula for this.
A white precipitate is formed which is soluble in dilute ammonia solution. Ag+ + Cl- —> AgCl↓
What is the anion test for sulfate or sulfite ions? (2)
- Add BaCl2 solution to a solution of the solid.
2. Distinguishing test. Add dilute HCl
What observations are made for the test for sulfate or sulfite ions? Give the formula for this and for distinguishing between both.
Ba2+ + SO4^2- –> BaSO4↓
Ba2+ + SO3^2- –> BaSO3↓
Distinguishing:
BaSo4 + HCl –> no reaction
SO3^2- + 2H+ –> SO2 + H2O
What is the anion test for carbonate or hydrogen-carbonate ions? (2)
- Add dilute HCl to the solid.
2. Distinguishing test. Add MgSO4 to a fresh solution of the solid.
What observations are made for the test for carbonate or hydrogen-carbonate ions?
Give the formula
1. for the fizzing of both,
2. The limewater turning milky
3. the precipitate formed for distinguishing between both. (6)
- Fizzing (carbonate):
CO3^2- + 2H+ –> CO2 + H2O
Fizzing (hydrogen-carbonate):
HCO3^- + H+ –> CO2 + H2O
- Ca(OH)2 + CO2 –> CaCO3↓ + H2O
- Precipitate:
Mg2+ + CO3^2- –> MgCO3 ↓
Mg2+ + 2HCO3- —> Mg(HCO3)2
boil hydrogen carbonate
Mg(HCO)3 –> MgCO3↓ + CO2 + H2O
What is the anion test for nitrate ions?
Brown ring test. To a solution of the solid add a freshly prepared FeSO4 solution. Add concentrated sulfuric acid.
What observations are made for the test for nitrate ions?
A brown ring is formed at the junction of the two liquids. Nitrate ions are present.
The brown ring is due to the presence of nitrate ions.
What is the anion test for phosphate ions?
Ammonium molybdate is added to a solution of the solid. Concentrated sulfuric acid is added. Solution is warmed.
What observations are made for the test for phosphate ions?
Yellow precipitate is formed.
Phosphate ions are present.
