chem Flashcards
Ammonium (NH₄⁺) + NaOH
No precipitate, but produces ammonia on warming.
Calcium (Ca²⁺) + NaOH
White precipitate, insoluble in excess NaOH.
Copper(II) (Cu²⁺) + NaOH
Light blue precipitate, insoluble in excess NaOH.
Iron(II) (Fe²⁺) + NaOH
Green precipitate, turns brown if left standing.
Iron(III) (Fe³⁺) + NaOH
Red-brown precipitate, insoluble in excess NaOH.
Zinc (Zn²⁺) + NaOH
White precipitate, redissolves in excess NaOH to give a clear solution.
Ammonium (NH₄⁺) + NH₃
No reaction.
Calcium (Ca²⁺) + NH₃
No precipitate or very slight white precipitate.
Copper(II) (Cu²⁺) + NH₃
Light blue precipitate, dissolves in excess NH₃ to form dark blue solution.
Iron(II) (Fe²⁺) + NH₃
Green precipitate, turns brown if left standing.
Iron(III) (Fe³⁺) + NH₃
Red-brown precipitate, insoluble in excess NH₃.
Zinc (Zn²⁺) + NH₃
White precipitate, redissolves in excess NH₃ to form a clear solution.
Carbonate (CO₃²⁻) Test
Add dilute HCl → Effervescence (CO₂ gas). Test with limewater.
Chloride (Cl⁻) Test
Acidify with HNO₃, add AgNO₃ → White precipitate (AgCl).
Bromide (Br⁻) Test
Acidify with HNO₃, add AgNO₃ → Cream precipitate (AgBr).
Iodide (I⁻) Test
Acidify with HNO₃, add AgNO₃ → Yellow precipitate (AgI).
Sulfate (SO₄²⁻) Test
Acidify with HCl/HNO₃, add Ba²⁺ solution → White precipitate (BaSO₄).
Nitrate (NO₃⁻) Test
Add NaOH, aluminum foil, warm → Ammonia gas given off (moist red litmus turns blue).
