Chem Mod 8 - Cations/Anions Flame Test

Lead (II)

White precipitate with HCl; white precipitate with NaOH (dissolves in excess).

Silver (Ag⁺)

White precipitate with HCl; brown precipitate with NaOH (doesn’t dissolve).

Barium (Ba²⁺)

No precipitate with HCl; white precipitate with Na₂SO₄; green flame test.

Calcium (Ca²)

No precipitate with HCl; white precipitate with Na₂SO₄; brick red flame test.

Copper (Cu²⁺)

No precipitate with HCl; blue precipitate with NaOH; blue copper compounds.

Iron (III) (Fe³⁺)

No precipitate with HCl; brown precipitate with NaOH; deep red solution with thiocyanate.

Iron (II) (Fe²⁺)

No precipitate with HCl; pale green precipitate with NaOH; decolorizes potassium permanganate.

Aluminium (Al³⁺)

No precipitate with HCl; white precipitate with NaOH (dissolves in excess).

Magnesium (Mg²⁺)

No precipitate with HCl; white precipitate with NaOH.

Chloride (Cl⁻)

No precipitate with HNO₃; white precipitate with AgNO₃; dissolves in dilute NH₃.

Bromide (Br⁻)

No precipitate with HNO₃; pale yellow precipitate with AgNO₃; dissolves in concentrated NH₃.

Iodide (I⁻)

No precipitate with HNO₃; yellow precipitate with AgNO₃; lead iodide is bright yellow.

Hydroxide (OH⁻)

No precipitate with HNO₃; brown precipitate with AgNO₃; green/cyan precipitate with iron (II).

Carbonate (CO₃²⁻)

Bubbles with HNO₃ (CO₂ release); effervescence with HCl.

Sulfate (SO₄²⁻)

No precipitate with HNO₃; white precipitate with Ba(NO₃)₂; precipitates in acidic conditions.

Phosphate (PO₄³⁻)

No precipitate with HNO₃; white precipitate with Ba(NO₃)₂; precipitates with NaOH.

Acetate (CH₃COO⁻)

No precipitate with HNO₃; no precipitate with AgNO₃; red precipitate with iron (III) chloride.

Barium vs Calcium

Add fluoride; calcium forms white precipitate, barium does not.

Lead vs Silver

Add NaOH; lead forms white precipitate (dissolves), silver forms brown precipitate (doesn’t dissolve).

Phosphate vs Sulfate

In acidic conditions, sulfate precipitates, phosphate does not.