This document provides information on common cation and anion tests in chemistry. It lists several cations (aluminum, ammonium, calcium, copper, iron, zinc, lead) and their reactions when aqueous sodium hydroxide or ammonia is added. Precipitates formed are identified. It also lists several anions (carbonate, chloride, iodide, nitrate, sulfate) and their confirmatory chemical tests involving reactions like the formation of gases, precipitates with silver or barium salts, or color changes. The document serves as a reference for students to identify common metal cations and inorganic anions through characteristic chemical reactions.

1. Chemistry notes grade 9 DhiffushiSchool
Test for cations and anions Page 1
TEST FOR ANIONS AND CATIONS
Cat ion Formula
Effect of aqueous sodium
hydroxide (NaOH)
Effect of aqueous ammonia (NH3)
Reaction producing precipitate
Aluminium
Al3+
White precipitate formed, soluble in
excess and forms a colourless
solution of complex ions.
White precipitate formed, insoluble in excess Al3+
+ 3OH-
→ Al(OH)3
(white ppt)
Al(OH)3 + OH-
→ [Al(OH)4] Colourless complex
Ammonium
NH+
No precipitate formed, ammonia gas
produced on warming
No reaction
-
Calcium
Ca2+
White precipitate formed, insoluble
in excess.
No precipitate formed.
Ca2+
+ 2OH-
→ Ca(OH)2
Copper (II)
Cu2+
Light blue precipitate formed,
insoluble in excess.
Blue precipitate formed, soluble in excess to
form a dark blue solution of complex ions
Cu2+
+ 2OH-
→ Cu(OH)2
Cu(OH)2+ 4NH3→2OH-
+ [Cu(NH3)4]2+
Iron (II)
Fe2+
Green precipitate formed, insoluble
in excess.
Green precipitate formed, insoluble in excess. Fe2+
+ 2OH-
→ Fe(OH)2
Iron (III)
Fe3+
Reddish brown precipitate formed,
insoluble in excess.
Brown precipitate formed, insoluble in
excess.
Fe2+
+ 2OH-
→ Fe(OH)3
Zinc
Zn2+
White precipitate formed, soluble in
excess, form a colorless solution
White precipitate formed, soluble in excess,
form a colorless solution of complex ions
Zn2+
2OH-
→ Zn(OH)2
Zn(OH)2+ 4NH3→[Zn(NH3)4]2+
Lead
Pb2+
White precipitate formed, soluble in
excess, from a colourless solution.
White precipitate formed, insoluble in excess. Fe2+
+ 2OH-
→ Pb(OH)2

2. Chemistry notes grade 9 DhiffushiSchool
Test for cations and anions Page 2
An ion formula Test Test result Reaction that occur
Carbonate CO3
2-
Add dilute hydrochloric acid.
Effervescence observed, when gas evolved is passed
through limewater, a white precipitate is formed. The
gas is carbon dioxide.
CO3
2-
+ 2H+ → CO2 + H2O
Ca(OH)2 + CO2 → CaCO3 + H2O
Chloride Cl-
Add aqueous silver nitrate solution.
White precipitate, insoluble in dilute nitric acid but
soluble in aqueous ammonia.
Ag+
+C I-
→ AgCl
White precipitate
Pb+
+ 2Cl-
→ PbCl2
y ellow precipitateAdd acidified lead (II) nitrate solution. A white precipitate is formed.
Iodide I-
Add aqueous silver nitrate. Yellow precipitate is formed, insoluble in both nitric acid
and aqueous ammonia.
Ag+
+ I-
→ AgI
White precipitate
Pb+
+ 2l-
→ Pbl2
y ellow precipitate
Add acidified lead (II) nitrate solution. A yellow precipitate is formed.
Nitrate NO3
-
Add aqueos sodium hydroxide then
warm the mixture with aluminium foil.
Effervescence observed, a pungent smelling gas is
produced. This turns moist red litmus paper blue.
A dense white fume of a gas is formed with
concentrated hydrochloric acid.
NH3 + HCl → NH4Cl
Sulfate SO4
2-
Acidify with dilute hydrochloric acid,
and then add aqueous barium
chloride. Or Acidify with dilute nitric
acid, then add aqueous barium
nitrate.
A white precipitate is formed.
Ba2+
+ SO4
2-
→ BaSO4
white precipitate