Ion Tests

Monitoring and Management‎ > ‎3. Manufactured Products‎ > ‎

Deduce the ions present in a sample from the results of tests

Perform first-hand investigations to carry out a range of tests, including flame tests, to identify the following ions:

    • phosphate
    • sulfate
    • carbonate
    • chloride
    • barium
    • calcium
    • lead
    • copper
    • iron
Cation
Precipitate test(s)
Flame test(s)
Other Test(s)
Barium (Ba2+)
• SO42-: White

• OH or F+: None

Yellowgreen
Calcium (Ca2+) SO42-: White
• F: White
Orangered
Lead (Pb2+) • Cl: White
• I: Yellow


Copper (Cu2+) OH: Blue, dissolves in NH3 to form deep blue
solution
Bluegreen
Iron II (Fe2+) OH: White, turns brown
Decolourises dilute potassium permanganate
solution
Iron III (Fe3+) OH: Brown
SCN: Deep red solution
Cation tests

 

Cation
Precipitate test(s)
Other test(s)
Carbonate (CO32-)
• pH between 8 and 11.
• Acid (H+): Bubbles of colourless odourless gas (CO2)
Sulfate (SO42-) • Ba(NO3)2 (to acidified sample): Thick white
• Pb(NO3)2 (to acidified sample): White

Chloride (Cl) AgNO3 (to acidified sample): Thick white, dissolves in ammonia and darkens in sunlight
Phosphate (PO43-) • NH4 followed by Ba(NO3)2: White
• Mg2+ in an ammonia, ammonium nitrate buffer: White

Anion tests


Copper flame test