This document summarizes a series of experiments to analyze an unknown salt sample. Preliminary tests on the salt indicate it is likely a metal salt based on color changes. Further tests are used to identify the anion as nitrate (NO3-) based on gas evolution reactions. Additional confirmatory tests confirm the presence of nitrate ions. Cation analysis indicates the presence of ammonium (NH4+) based on gas evolution and confirmatory tests. In summary, the salt is identified as ammonium nitrate based on a series of qualitative chemical analyses to identify the constituent ions.

1. Salt Analysis
S
No.
Experiment Observation Inference
1) Preliminary Tests
1) Colour:
Light Green May be Fe+2
Salt.
Light Pink May be Mn+2
Salt.
Greenish May be Ni+2
Salt.
Pink May be Co+2
Salt.
Colourless Absence of the above salts.
2) Physical state: Crystalline/Amorphous
3)
Action of heat:
A pinch of salt is taken in a dry
test tube & heated strongly.
White sublimate is formed. May be NH+4
salt.
Reddish brown vapours are evolved. May be NO-
3 salt.
Crackling sound is observed. May be Pb+2
salt.
Water drops are formed along the inner
walls of the test tube.
May be hydrated salt.
Yellow when hot & while when cold. May be Zn+2
salt.
Characteristic vinegar like smell. May be CH3COO-
salt.
4)
Flame test:
A paste of the salt with Con.HCl
prepared put on the top of the
flame.
Brick red flame May be Ca+2
salt.
Apple green flame May be Ba+2
salt.
Crimson red flame May be Sr+2
salt.
Green flashes May be Zn+2
salt.
No characteristic flame is observed. Absence of the above salts.
2) Identification of Anion
1)
Test with dil.HCl:
Take a pinch of salt in a dry test
tube & add dil.HCl.
(i) Colourless & Odourless Gas of CO2 is
evolved with brisk effervescence which
puts out the burning splinter & turns lime
water milky.
CO3
-2
may be present.
(ii) Colourless vapours of CH3COOH
with vinegar smell are evolved, which
turns blue litmus red.
CH3COO-
may be present.
(iii)No characteristic reaction. CO3
-2
& CH3COO-
[Absent]
2)
Test with Con.H2SO4:
Take a small quantity of the salt in
a dry test tube & add Con.H2SO4.
(i) Colourless gas with pungent smell
(HCl) is evolved. It produced white
dense fumes when a glass rod dipped in
NH4OH is placed at the mouth of the test
tube.
Cl-
may be present.
(ii) Reddish brown vapours with pungent
smell are evolved.
Br-
may be present.
(iii) No characteristic reaction. Cl-
& Br-
ions are absent.
3)
Test with BaCl2:
To the salt solution add BaCl2
solution.
White crystalline precipitate of barium
sulphate is formed.
SO4
-2
may be present.
No precipitate is formed. SO4
-2
is absent.
4)
Test with Con.H2SO4 [Hot]:
Take a small quantity of the salt in
a test tube, add Con.H2SO4 & heat.
Reddish brown vapours of NO2 are
evolved.
NO3
-
may be present.
Reddish brown vapours of NO2 are not
evolved.
NO3
-
is absent.
Test with Cu turnings &
Con H2SO4:
Take a small quantity of the salt in
a test tube, add a few Cu turnings,
add Con. H2SO4 & heat strongly.
Deep reddish brown vapours of NO2 are
evolved & the solution turns pale blue.
NO3
-
may be present.
No reddish brown vapours are evolved. NO3
-
is absent.

2. 3) Confirmatory test for Anion
1. Confirmatory test for Cl-
ion
1)
Test with MnO2 &
Con.H2SO4:
Take a small quantity of the salt
in a test tube, add MnO2,
Con.H2SO4 & heat.
Greenish yellow gas of chlorine with
pungent smell is evolved which turns
moist starch iodide paper blue.
Cl-
is confirmed.
2)
Take salt solution & acidify it
with dil. HNO3 & add AgNO3
solution.
A white curdy precipitate of AgCl is
formed which is soluble in NH4OH.
Cl-
is confirmed.
2. Confirmatory test for Br-
ion
1)
Test with MnO2 &
Con.H2SO4:
Take a pinch of salt in a test
tube, add MnO2 & Con.H2SO4
Reddish brown vapours of Br with
pungent smell are evolved which turns
starch paper yellow.
Br-
is confirmed.
2)
Take salt solution & acidify it
with dil.HNO3 & add AgNO3
solution.
Pale yellow precipitate of AgBr is
formed which is partially soluble in
NH4OH.
Br-
is confirmed.
3. Confirmatory test for NO3
-
1)
Brown ring test:
Take the salt solution in a test
tube & add freshly prepared
FeSO4 solution in excess.
To this Con.H2SO4 is added
slowly along the sides of the test
tube in an inclined position.
A dark brown ring is formed at the
junction of the two layers.
NO3
-
is confirmed
4. Confirmatory test for CO3
-2
1)
Test with BaCl2:
Take the salt solution in a test
tube & add BaCl2 solution.
A white precipitate of barium carbonate
(BaCO3) is formed. This precipitate is
soluble in dil.HCl.
CO3
-2
is confirmed.
5. Confirmatory tests for CH3COO-
1)
Test with neutral FeCl3 sol:
Take the solution in test tube,
add neutral FeCl3 sol & boil the
above solution in water bath.
Deep in red colour solution is formed. CH3COO-
is confirmed.
2)
Esterification:
Take a pinch of salt in a test
tube, add C2H5O, Con.H2SO4,
heat the contents & pour into a
beaker containing H2O.
Pleasant fruity odour (C4H8O2, ethyl
acetate) is observed.
CH3COO-
is confirmed.
6. Confirmatory test for SO4
-2
1)
To the salt solution add BaCl2
solution.
The solubility of the precipitate
is tested in Con.Hcl
White crystalline precipitate of BaSO4
is formed.
The precipitate is insoluble in Con.Hcl
SO4
-2
is confirmed.

3. 4) Identification of Cation
 Analysis of NH4
+
1)
Take a pinch of salt in a test tube,
add NaOH & heat.
Colourless gas with characteristic
NH4
+
smell is evolved, which gives
white dense fumes when a glass rod
dipped in Con.HCl is brought near the
mouth of the test tube.
NH4
+
may be present.
NH4
+
gas is not evolved. NH4
+
is absent.
 Confirmatory test for NH4
+
1)
To the salt solution add K2HgI4
(Nessler’s reagent/Potassium
mercuric iodide).
Reddish brown precipitate
(NH2HgOHgI, Iodide of Millions
base) is formed.
NH4
+
is confirmed.
 Preparation of original solution
1)
The salt is dissolved in H2O/ dil.HCl
solvent.
Clear & transparent solution is
formed.
It is original solution.(O.S)
1. Analysis of Group – I
1) To the O.S add dil.HCl.
White precipitate is formed. Group-I is present (Pb+2
)
No white precipitate is formed. Group-I is absent.
2. Analysis of Group – III
1)
To the O.S add solid NH4Cl, excess
of NH4OH.
White gelatinous precipitate is formed. Group-III (Al+3
) is present.
No precipitate is formed. Group-III is absent.
3. Analysis of Group – V
1)
To the O.S add solid NH4Cl, excess
of NH4OH & (NH4)2CO3 solution.
White precipitate is formed.
Group - V Cations are present
(May be Ba+2
or Ca+2
or Sr+2
)
White precipitate is not formed. Group - V Cations are absent.
4. Analysis of Group – VI
1)
To the O.S add NH4Cl, NH4OH &
Na2PO4.
White precipitate is formed. Mg+2
may be present.
5) Confirmatory tests for Cation
1. Confirmatory tests for Pb+2
[Group-I]
Dissolve the precipitate in hot water & divide it into two parts.
i) To the 1st
part add K2CrO4 solution.
Yellow precipitate is formed which
dissolves in NaOH solution.
Pb+2
is confirmed.
ii) To the 2nd
part add KI solution.
Yellow precipitate is formed which
dissolves in hot water & on cooling
the solution forms golden spangles.
Pb+2
is confirmed.
2. Confirmatory test for Al+3
[Group –III]
1) To the O.S add NaOH solution.
White gelatinous precipitate is formed,
which is soluble in excess of NaOH.
Al+3
is confirmed.
3. Confirmatory test for Zn+2
[Group –IV]
1) To the O.S add NaOH solution.
White precipitate is formed, which is
soluble in excess of NaOH.
Zn+2
is confirmed.
4. Confirmatory tests for Ba+2
, Ca+2
& Sr+2
[Group -V]
1) To the O.S add K2CrO4 solution.
Yellow precipitate (BaClO4) is
formed, which is soluble in Con.HCl.
Ba+2
is confirmed.
Yellow colour is formed. Ca+2
is confirmed.
2)
To the O.S add (NH4)2SO4 solution
& warm it. Scratch the inner sides of
the test tube with a glass rod.
White precipitate is formed. Sr+2
is confirmed.
5. Confirmatory test for Mg+2
[Group –VI]
1) To the O.S add (NH4)2CO3 solution.
White precipitate is formed which is
soluble in NH4Cl solution
Mg+2
is confirmed.