class 12 salt analysis

1. SALT ANALYSIS
SCHEME OF ANALYSIS
EXPERIMENT OBSERVATION INFERENCE
PRELIMINARY EXAMINATIONS :
1) Noted the colour Colourless Absenceof
Cu2+
,Fe2+
,Fe3+
,Mn2+
,Co2+
,Ni2+
Blue Pre. of Cu2+
Brown Pre. of Fe3+
Green Pre. of Ni2+
Pale pink Pre. of Mn2+
Pink Pre. of Co2+
2) Noted the solubility
a) In water
b) In dil.HCl
a) Soluble and no
ppt with Na2CO3
b) Insoluble
a) Pre. of NH4
+
b) Pre. of Pb2+
3) Flame Test :
A little of the salt is made into
paste with conc.HCl. A glass rod
is dipped in it and introduced
into the flame.
a) Blue surrounded
by green
b) Brick red
c) Crimson red
d) Bluish white
e) Grassy green on
prolonged
heating
a) Pre. of Cu2+
b) Pre. of Ca2+
c) Pre. of Sr2+
d) Pre. of Pb2+
e) Pre. of Ba2+
4) Ash Test :
A little of the salt is heated with
con.HNO3 and cobalt nitrate
solution. A filter paper is
dipped in it and burnt.
a) Green ash
b) Blue tinted ash
c) Pale pink ash
a) Pre. of Zn2+
b) Pre. of Al3+
c) Pre. of Mg2+
SYSTEMATIC ANALYSIS OF ANIONS :
1) Dil.H2SO4 test :
To the salt add dil.H2SO4, warm
if required.
a) Evolution of
Colourless,
odourless gas
with brisk
effervescence,
turns limewater
milky.
b) Smell of vinegar
a) Pre. of carbonates
b) Pre. of acetate

2. 2) Conc.H2SO4 test :
Treat a small quantity of the
salt with Conc.H2SO4, warmif
necessary.
a) Colourless gas
with pungent
smell, give dense
white fumes
when a glass rod
dipped in NH4OH
is shown.
b) Brown gas with
pungent smell
c) Violet vapours
with pungent
smell
d) Light brown gas
with pungent
smell on strong
heating.
e) Smell of vinegar
a) Pre. of Cl-1
b) Pre. of Br-1
c) Pre. of I-1
d) Pre. of NO3
-1
e) Pre. of CH3COO-1
3) Paper ball test :
Heat a little of the salt with
Conc.H2SO4 and introduce a
paper ball to it.
Brown fumes Pre. of NO3
-1
4) Test for sulphates :
Heat a little of the salt solution
with dil.HCl and add BaCl2
solution.
White ppt insoluble in
Conc.HCl
Pre. of sulphate
5) Test for phosphates :
Add Conc.HNO3 to the salt
solution and boil. Add exess of
ammonium molybdate solution
and boil again.
Yellow ppt Pre. of phosphate
CONFIRMATORY TEST FOR ANIONS :
1) Carbonates :
Magnesium sulphate test :
To the salt solution add MgSO4
solution.
White ppt Pre. of carbonates confirmed
2) Chlorides :
a) MnO2 test :
Heat a smallquantity of salt
with Conc.H2SO4 and MnO2
.
a) Greenish yellow
gas with pungent
smell
Pre. of chloride confirmed

3. b) Chromylchloride test :
Salt is heated with
conc.sulphuric acid and
pot.dichromate.
The vapours arecollected
and passed through NaOH
solution.
Add lead acetate solution to
this.
c) Silver nitrate test :
Acidify the salt solution with
dil.nitric acid and add silver
nitrate solution.
b) Reddish brown
vapours
Yellow solution
Yellow ppt
c) White curdy ppt
soluble in excess
of NH4OH
Pre. of chloride confirmed
Pre. of chloride confirmed
3) Acetates :
a) Oxalic acid test :
Make a paste of the salt
with oxalic acid. Rub the
paste and smell.
b) Ester test :
To the salt add conc.H2SO4
and heat. Add alcohol.
Shake. Pour the contents
into a beaker containing
water.
c) Ferric chloride test :
To the salt solution add
neutral ferric chloride
solution. Filter. Dividethe
filtrate into two portions :
I. To one add dil.HCl.
II. To the second, add
water and boil
a) Smell of vinegar
b) Pleasant fruity
smell
c) Reddish coloured
ppt
I. Reddish colour
disappears
II. Reddish ppt
Pre. of acetate
Pre. of acetate confirmed
Pre. of acetate confirmed
4) Sulphate :
a) To the salt solution add
dil.HCl and barium chloride
solution.
b) To the salt solution add
acetic acid and lead acetate
solution.
White ppt insoluble in
HCl
White ppt solublein hot
ammonium acetate
Pre. of sulphate confirmed
Pre. of sulphate confirmed
5) Phosphate:
a) Ammonium molybdatetest :
To salt solution add
conc.HNO3 and boil. Add
ammonium molybdate and
a) Yellow ppt Pre. of phosphate

4. heat again.
b) Magnesia mixture test :
To the salt solution add
magnesia mixture and allow
to stand.
b) White ppt Pre. of phosphateconfirmed.
6) Bromide :
a) To salt add conc.H2SO4 and
MnO2
b) To salt add dil.HCl and AgCl
a) Densebrown
fumes
b) Pale yellow ppt
partially soluble
inNH4OH
Pre. of bromide confirmed
Pre. of bromide confirmed
7) Nitrate :
a) To a little salt add
conc.H2SO4 and add cu
turnings and heat.
b) To salt solution add fresh
FeSO4 and cool. Add
conc.H2SO4
a) Brown vapours
and green
solution
b) Brown ring at the
junction between
two layer.
Pre. of nitrate confirmed
Pre. of nitrate confirmed
ANALYSIS OF CATIONS:
1) To the salt solution add sodium
carbonate solution
No ppt Pre. of zero group
(Ammonium)
2) To the solution add dil. HCl White ppt Pre. of group 1
(Pb2+
)
3) To the solution add dil. HCl and
pass H2S
Black ppt Pre. of group 2
(Cu2+
)
4) To the solution add solid
ammonium chloride and excess
of ammonium hydroxide
White gelatinous ppt Pre. of group 3
(Al3+
)
5) To the solution add solid
ammonium chloride and excess
of ammonium hydroxide. Pass
H2S
White ppt Pre. of group 4
(Zn2+
)
6) To the solution add solid
ammonium chloride and excess
of ammonium hydroxide. Add
ammonium carbonatesolution
White ppt Pre. of group 5
(Ba2+
,Sr2+
,Ca2+
)
7) To the solution add solid
ammonium chloride and excess
of ammonium hydroxide. Add
sodium hydrogen phosphate
White ppt Pre. of group 6
(Mg2+
)

5. ANALYSIS OF GROUP 0(AMMONIUM)
1) To the salt solution add NaOH
solution. Warm
Smell of ammonia.
Gives white dense
fumes when a glass rod
dipped in HCl is
introduced.
Pre. of ammonium confirmed
2) To the salt solution add NaOH
solution. Warm. Add Nesslers
reagent
Brown ppt Pre. of ammonium confirmed
ANALYSIS OF GROUP 1(LEAD)
1) Potassium iodide test :
To the salt solution add KI
solution
Yellow ppt Pre. of lead confirmed
2) Potassium chromate
test :
To the salt solution add
k2CrO4 solution
Yellow ppt Pre. of lead confirmed
ANALYSIS OF GROUP 2(Copper)
1) To the salt solution add few
drops of potassium
ferrocyanidesolution and
acetic acid.
Chocolate coloured
precipitate
Pre. of Cu2+
confirmed
2) To the salt solution add acetic
acid and potassium iodide
solution.
White ppt Pre. of Cu2+
confirmed
3) To the salt solution add NH4OH
solution.
Deep blue colour Pre. of Cu2+
confirmed
ANALYSIS OF GROUP 3(Aluminium)
1) The white ppt obtained is
dissolved in dil.HCl
Add 2 drops of blue litmus
solution. Then add ammonium
hydroxidedropwisetill blue
colour develops.
Blue ppt floating in
colourless solution
Pre. of aluminium confirmed
2) Add excess of NaOH to the salt
solution
White ppt solublein
excess of NaOH
Pre. of aluminium confirmed

6. 3) Ash test is conducted with the
group ppt
Blue ash Pre. of aluminium confirmed
ANALYSIS OF GROUP 4(Zn2+
)
1) The white ppt obtained in gp.4
is dissolved in dil.HCl
And divided into two
a) To one part add NaOH in
drops
b) To the second part add
pot.ferrocyanidesolution
a) White ppt soluble
in excess of NaOH
b) White/bluish
white ppt
Pre. of Zn2+
confirmed
Pre. of Zn2+
confirmed
2) Ash test is conducted with the
group ppt
Green ash Pre. of Zn2+
confirmed
ANALYSIS OF GROUP 5(Ba2+
,Sr2+
,Ca2+
)
Test for Ba :
Potassium chromatetest :
1) To the salt solution add K2CrO4
solution.
2) Flame test is conducted with
the group ppt.
1) Yellow ppt
2) Grassy green
flame
Pre. of Ba confirmed
Pre. of Ba confirmed
Test for Sr :
1) Add ammonium sulphate to the
salt solution.
2) Flame test is conducted with
the group ppt.
1) White ppt
2) Crimson red
flame
Pre. of Sr confirmed
Pre. of Sr confirmed
Test for Ca :
1) To the salt solution add
ammonium oxalate solution.
2) Flame test is conducted with
the group ppt.
1) White ppt
2) Brick red flame
Pre. of Ca confirmed
Pre. of Ca confirmed
ANALYSIS OF GROUP 6(Mg2+
)
Test for Mg2+
:
1) To the salt solution add
ammonium phosphate
solution.
2) Ash test is conducted with
group ppt
1) White ppt
2) Pale pink ash
Pre. of magnesium confirmed
Pre. of magnesium confirmed