This document describes confirmatory tests for several metal ions and ammonium ion. Iron(II) ions react with potassium hexacyanoferrate(III) solution to form a dark blue precipitate. Tests for lead(II) ions include using chloride or iodide ions, which form precipitates that dissolve in hot water but reappear in cool water. Ammonium ion can be tested by heating with an alkali to produce ammonia gas, or using Nessler's reagent to form a brown precipitate. Confirmatory tests are summarized along with expected observations and conclusions.

3. Confirmatory test for Iron(II)
ion and Iron(III) ion.
REAGENT OBSERVATION CONCLUSION
1. potassium
hexacyanoferrate(II)
solution
Pale blood Iron(III)ion is present
Dark precipitate Iron(III)ion is present
2. potassium
hexacyanoferrate(III)
solution
Dark blue Iron(III)ion is present
Greenish-brown
solution
Iron(III)ion is present
3. potassium
thiocyanate solution
(ammonium thiocyanate
solution)
Pale red colouration Iron(III)ion is present
Blood red colouration Iron(III)ion is present

4. REAGENT METHOD OBSERVATION CONCLUSION
Using
aqueous
solution of
chloride ions
1. 2cm of potassium chloride solution
(any solution of chloride ion) is
poured into 2cm of solution to be
test
2. The contents obtained are then
diluted are with 5cm of distilled
water and heated until no further
change occur
3. The contents are then allowed to
cool to room temperature using
running water from the tap
• A white precipitate is
formed
• When heated, the
precipitate dissolves
in hot water to form a
colourless solution
• On cooling to room
temperature, the
white precipitate
reappears.
Pb + 2Cl PbCl
Lead(II) chloride is soluble
in hot water but insoluble
in cool water.
The white precipitate
formed is Lead(II)
chloride. Lead(II) ion is
confirmed present in the
solution.
Using
aqueous
solution of
iodide ions
1. 2cm of potassium iodide solution
(any solution of iodide ion) is
poured into 2cm of solution to be
test
2. The contents obtained are then
diluted are with 5cm of distilled
water and heated until no further
change occur
3. The contents are then allowed to
cool to room temperature using
running water from the tap
• A yellow precipitate is
formed
• When heated, the
precipitate dissolves
in hot water to form a
colourless solution
• On cooling to room
temperature, the
yellow precipitate
reappears.
Pb + 2L PbL
Lead(II) iodide is soluble
in hot water but insoluble
in cool water.
The yellow precipitate
formed is Lead(II) iodide.
Lead(II) ion is confirmed
present in the solution.
Confirmatory test for lead(II)
ion
2+ +
2+ -
2
2

5. Confirmatory test for ammonium
ion
REAGEN
T
METHOD OBSERVATION CONCLUSIO
N
Heating an
ammoniu
m salt with
an alkali
1. One spatula of solid salt to be tested
(or its aqueous solution) is mixed with
one spatula of solid sodium
hydroxide/ potassium hydroxide/
calcium hydroxide (or it’s aqueous
solution) in a test tube
2. The mixture is heated
3. A piece of moist red litmus paper is
held at the mouth of the test tube
4. The changes that occur are recorded
• A colourless gas that
turns moist red litmus
paper to blue is liberated
The gas
liberated is
ammonia.
Ammonium
ion, NH is
confirmed
present in
solid salt
Reaction
with
Nessler’s
reagent
1. 2 cm of an aqueous solution salt to
be tested is poured into a test tube
2. 2cm of Nessler’s reagent is then
added to the test tube and shaken
well
3. The changes are recorded
• A brown precipitate is
formed
• Nessler’s reagent is an
alkaline solution of
mercury(II) iodide in
potassium iodide and
sodium hydroxide
solution
• Nessler’s reagent
contains complex ions
Ammonium
ion is
confirmed
present in
solid salt

6. Cation
confirmatory
test
Iron(II)
ions
Iron(III)
ions
Lead(II)
ions
Ammonium
ions
Potassium
hexacyanoferrate
(III) solution
Potassium
thiocyanate
solution
Potassium
iodide solution
Nessler’s
reagent
Dark blue
precipitate
Blood red
colouration
Yellow
precipitate
Brown
precipitate

7. C
R
O
S
S
W
O
R
D
Horizontal:
1. Iron (II) ion react with potassium hexacyanoferrate (III) solution will formed _______.
2. Test for lead (II) ions can use two reagents which is using aqueous solution of
iodide ions and _____ ions.
3. Lead (II) chloride is ____ in hot water but insoluble in cool water.
4. When ___, the precipitate (of lead (II) ion) dissolves in hot water to form a colourless
solution.
5. Confirmatory test for ammonium ion can be test by using _________ litmus paper.
6. Ammonium ion is confirmed present in ___ salt.
7. By using aqueous solution of iodide ions, yellow precipitate reappears in _____ room
temperature.
Vertical:
8. Test for iron (III) ion that react with potassium thiocyanate solution will formed ____.
9. Test for ammonium ion by reaction with Nessler’s reagent will formed a ___
precipitate.
10. Test for lead (II) ion using chloride ions on cooling temperature the white precipitate
________.
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