FOR EDUCATION ANALYSIS

1. QUALITATIVE
ANALYSIS
• Qualitative analysis is a chemical technique used to determine what
substances are present in a mixture but not their quantities.
• In the qualitative analysis of salts, we need to identify the ions that are
present in salts.
• This can be done by analysing their physical and chemical properties.

2. Colour and solubility in water
Salt Colour in solid Solubility in water Colour in Aqueous
solution
1. Ammonium chloride NH4Cl white soluble colourless
2. Ammonium nitrateNH4(NO3)3 white soluble colourless
3. Calcium carbonate CaCO3 white insoluble -
4. Calcium nitrate Ca(NO3)2 white soluble colourless
5. Magnesium sulphate MgSO4 white soluble colourless
6. Magnesium carbonate MgCO3 white insoluble -
7. Zinc sulphate Zn SO4 white soluble colourless
8. Zinc nitrate Zn(NO3)2 white soluble colourless
9. Lead(II) chloride , PbCl2 white insoluble -
10. Lead(II) sulphate , PbSO4 white insoluble -

3. 11. Lead(II) carbonate , PbCO3 white insoluble -
12. Copper(II) chloride , CuCl2 Blue soluble Blue
13 Copper(II) sulphate , PbSO4 Blue soluble Blue
14. Copper(II) carbonate ,
PbCO3
Green insoluble -
15. Iron(II) sulphate , FeSO4 Green soluble Pale green
16. Iron(III) chloride , FeCl3 Brown / Yellow soluble Brown/Yellow/
Yellowish brown
17. Sodium nitrate , NaNO3 white soluble colourless
18, Sodium carbonate , Na2CO3 white soluble colourless
19. Potassium nitrate , KNO3 white soluble colourless
20. Potassium carbonate , K2CO3 white soluble colourless
Colour and solubility in water

4. The table shows the colour of different cations in the solid form or in
aqueous solution
Observation Inference
Blue solution Ion copper (Cu2+ ) present
Pale green solution Ion Iron(II) Fe2+ present
Yellow/Yellowish-brown/brown
solution
Ion Iron (III) Fe3+ present
Green solid Hydrated Fe 2+, CuCO3
Brown solid Hydrated Fe 3+ salt
White solid Salts of Na+ , K+ ,NH4
+, Mg 2+, Ca 2+ Al 3+ , Zn 2+,
Pb 2+ (If the anions are colourless)
Colourless solution Na+ , K+ ,NH4
+, Mg 2+, Ca 2+ , Al 3+ , Zn 2+, Pb 2+

5. Effect of Heat on Salt and Gas Tests
• Gas released can be identified through its colour, smell, action on moist litmus
paper when a salt is heated.
• Can identified the present of ion based on the colour of the residue and the gas
identified.

6. Tests for anions
Reagent / Condition Observation Anion Ionic Equation (if
any)
2 cm3 the unknown solution
+ dilute hydrochloric acid /
nitric acid / sulphuric acid 
pour into a test tube  gas
liberated is immediately
bubbled through lime water.
Effervescence.
Colourless gas
turns lime water
milky.
CO3
2- ion CO3
2- + 2H+ 
CO2 + H2O
2 cm3 of nitric acid + 2 cm3 of
the unknown solution 
pour into a test tube  + 2
cm3 silver nitrate solution
White precipitate
is formed.
Cl- ion Ag+ + Cl-  AgCl

7. Reagent / Condition Observation Anion Ionic Equation (if any)
2 cm3 of dilute hydrochloric acid / nitric
acid + 2 cm3 of the unknown solution 
pour into a test tube  + 2 cm3 of
barium chloride / barium nitrate solution
 shake well
White precipitate is
formed.
SO4
2- ion Ba2+ + SO4
2 - 
BaSO4
2 cm3 of the unknown solution  pour
into a test tube 
2 cm3 of dilute sulphuric acid + 2 cm3 of
iron(II) sulphate solution  shake well.
Then drop carefully and slowly a few
drops of concentrated sulphuric acid
along the side of a slanting test tube
into the mixture without shaking it.
Brown ring is formed at
the boundary between
the concentrated H2SO4
(top layer) and aqueous
solution of the mixture
(bottom layer)
NO3
- ion -
Tests for anions

8. Confirmatory Test for Fe2+, Fe3+Ions
Reagent Observation Conclusion
Potassium
hexacyanoferrate(II)
solution
Pale blue precipitate Fe2+ ion is present
Dark blue precipitate Fe3+ ion is present
Potassium
hexacyanoferrate(III)
solution
Dark blue precipitate Fe2+ ion is present
Greenish-brown
solution
Fe3+ ion is present
Potassium thiocyanate
solution
Pale red colouration Fe2+ ion is present
Blood red colouration Fe3+ ion is present

9. Confirmatory Test for Pb2+
Method Observation Ionic Equation
 Using aqueous solution of chloride
- 2 cm3 of any solution of Cl- +
2 cm3 of any solution of Pb2+ 
dilute with 5 cm3 of distilled water 
heat until no further change occurs 
allow the content to cool to room
temperature using running water from
the tap
- A white precipitate is
formed
When heated – dissolve in
water to form colourless solution
When cooled – white precipitate
reappear
Pb2+ + 2Cl-  PbCl2
 Using aqueous solution of iodide
- 2 cm3 of any solution of I- +
2 cm3 of any solution of Pb2+ 
dilute with 5 cm3 of distilled water 
heat until no further change occurs 
allow the content to cool to room
temperature using running water from
the tap
- A yellow precipitate is
formed
When heated – dissolve in
water to form colourless solution
When cooled – yellow
precipitate reappear
Pb2+ + 2I-  PbI2

10. Confirmatory Test for NH4
+
Method Observation
 2 cm3 of any solution of NH4
+ + 2 cm3 of
NaOH / KOH / Ca(OH)2  heat  put a
piece of moist red litmus paper at the mouth
of the test tube
- Moist red litmus paper turns blue
Reaction with Nessler’s Reagent
 2 cm3 of any solution of NH4
+ + 2 cm3 of
Nessler’s Reagent  shake well
- A brown precipitate is formed

11. Test Cation with NaOH solution
Add a little
NaOH solution
Precipitate form?
No
Yes
Pb2+ Cu2+
Mg2+ Ca2+
Zn2+ Al3+ Fe2+ Fe3+
Dissolve  colourless Not dissolve
White precipitate Blue Dirty Green Brown
NH4
+
Add excess
K+
Na+

12. 12
Al3+, Zn2+, Pb2+, Mg2+, Ca2+, Fe2+, Fe3+, Cu2+

13. 13
Al3+, Zn2+, Pb2+, Mg2+, Ca2+, Fe2+, Fe3+, Cu2+