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8/3/2019 Element Analysis
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Certificate
This is to certify that the project entitled Dyes has been
submitted by Soumya Subhra Dutta a student of class
XII-A under the Roll no.__________ for the academic
session 2009-2010. He has completed the project work
Chemistry Department under direct supervision of the
undersigned as per the requirement for the Board
Examination.
(----------)
Department of Chemistry
----------------------
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ACKNOWLEDGEMENT
We want to express our sincere gratitude to our
Chemistry teacher Miss Rimpa Mukherjee for her
guidance, encouragement and kind co-operation without
which my chemistry project wont have been possible.
We are also grateful to Mr. Manojeet Das ,
LABORATORY ASSISTANT, CHEMISTRY
DEPARTMENT for his valuable help during the
preparation of this project.
SOUMYA SUBHRA DUTTA
XII-A
Roll No.________________
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GENERAL INTRODUCTION
Qualitative Analysis: The type of analysis that deals with themethods which are used to determine the constituents of acompound.
Radical: A radical is defined as an atom or group of atoms whichcarries charge and behaves as a single unit in chemical reactions.
Radicals carrying positive charge are called Basic Radicals andradicals carrying negative charge are called Acidic radicals.
Sublimation: It is a process by which a salt directly changes into agaseous phase without melting when heated. On cooling, vapourscondense back to the solid state.
Importance of Preliminary test in qualitative analysis
Preliminary tests give authentic information about an ion in the salt.For example, golden yellow color in flame test shows the presence ofsodium. In a charcoal cavity test, brown residue shows the presenceof cadmium in a salt and so on.
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Groups reagents for different groups
Group I Dilute HCl
Group II H2S in the presence of dil. HCl
Group III NH4OH in presence of NH 4Cl
Group IV H2S in presence of NH 4OH
Group V (NH4)2CO3 in presence of NH 4Cl and
NH4OH
Group VI NO specific reagent.
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List of Acid Radicals List of Basic Radicals
Cl- SO 42- NH4+ Mn2+
Br- PO43- Pb2+ Zn2+
I - CO32- Cu2+ Ba2+
NO3- SO 32- As3+ Sr 2+
CH3COO- S2- Fe3+ Ca2+
C2O42- NO2- Co2+ Mg2+
Ni2+
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PART I
Test Observations Inference
Dil. H 2S0 4 test : To a
small quantity of salt ,
1 -2 ml of dil. H 2SO4 is
added.
1) Colorless, odorless gas
with brisk effervense
turns water milky.
2) Colorless gas, pungent
smell, turns acidified
K2Cr2O7 paper green.
3) Colourless gas with
rotten egg smell, turns
lead acetate paper black.
4) Reddish brown gas,
pungent smell, turns
FeSO 4 black.
Gas Radical
CO2 CO32-
SO 2 SO 32-
H2S S 2-
NO2 NO2-
Chemicals Reactions involved in dil. H 2SO 4 test:
1) Carbonate: CaCO 3 + H2SO 4 CaSO4 + H2O + CO2
2) Sulphides: ZnS + H 2SO 4 ZnSO 4 + H2S
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3) Sulphites: Na 2SO 3 + H2SO 4 Na2SO 4 + SO2 + H2O
4) Nitrites: 3KNO 2 + 3H2SO 4 3KHSO4 + HNO3 + H2O + 2NO
2NO 2 + O2 2NO 2 (brown fumes)
PART II
Test Observations Inference
To a small quantity of slat
2-3 ml of concentrated
sulphuric acid is added.
1)Colorless gas with
pungent smell, white fume
with aqueous ammonia
NH4OH white ppt. AgNO 3
2) Reddish brown vapors
with pungent smell, turns
starch paper yellow. It
doesnt turn FeSO 4 soln
black.
3) Deep violet vapors with
Gas Radicals
HCl Cl-
Br2 Br-
I 2 I -
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Group Zero
Detection of NH 4+
Test Observation Inference
Nessler reagent test:
To the salt soltn few
drops of Nessler reagent
were added.
Brown ppt. formed (The
brown color is due to the
formation of
Mercuric Amido Iodide
[NH2.HgO.HgI] ).
NH4+ is present.
Chemical reactions involved in it are:
Nessler Reagent test:
2K2[HgI 4] + NH3 + 3KOH NH2.HgO.HgI + 7KI +
2H2O
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Group 1
Detection of Pb 2+ ion
Test Observation Inference
1) HCl test: To the salt
soln , dil. HCl is added to
the solution.
2) K2CrO4 test: To the
salt solution Potassium
chromate, K 2CrO4 is
added.
3) KI test: To the salt
soln Potassium Iodide is
added.
White ppt. of is formed
which is soluble in water.
Yellow ppt. is formed due
to formation of PbCrO 4.
Yellow ppt. is formed due
to the formation of PbI 2
which is soluble in hot
water reappears as
Golden spangles on
cooling.
Pb2+ is present.
Pb2+ is present.
Pb2+ is present.
Chemical reactions involved in it:
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HCL test: Pb (NO 3)2 + 2 HCl PbCl2 + 2HNO3
K2CrO4 test: PbCl 2 + K2CrO4 PbCrO4 + 2KCl
KI test: PbCl 2 + KI PbI 2 + 2KCl.
Detection of Cu2+
Test Observation Inference
Potassium Ferro cyanide
test: To the sample, few
drops of K 4[Fe(CN)6] is
added .
Chocolate Brown ppt. of
Cuprous Ferro cyanide
Cu[Fe(CN)6] is obtained.
Cu2+ is present
Chemical reactions involved in it are:
Potassium Ferro cyanide test: 2CuSO 4 + [Fe (CN)6] + 2 K2SO 4.
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Group II A
Detection of As 3+
Test Observation Inference
1) Ammonium molybdate
test: To a part of the
soln, add ammonium
molybdate and heat it.
2) Magnesia mixture
test: The second part of
the soln is made alkaline
with NH 4OH solution and
magnesia mixture is
added.
3) H2S gas test: The
salt soln is added with dil
H2S gas.
A yellow ppt. is formed.
A white ppt. is formed.
Yellow ppt. is formed.
As3+ is present.
As3+ is present.
As3+ is present.
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Group II B
Detection of Fe 3+
Test Inference Observation
Potassium Ferro
cyanide test: To the
sample, few drops of
K4[Fe(CN)6] is added .
Deep Blue coloration of
ferric ferro cyanide is
formed.
Fe3+ is present.
Chemical reactions involved in it are:
4FeCl3 + 3K4[Fe(CN)6] 12KCl + Fe[Fe(CN)6]3.
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Group III
Detection of Al 3+
Test Inference Observation
1) Lake Reaction: A
white ppt. Al(OH) 3 is
dissolved in dil HCl and
drop wise NH 4OH is
added till the blue color
develops.
2) Cobalt Nitrate test:
The salt is acted with
cobalt nitrate.
A blue lake is seen
Blue mass is produced.
Al3+ is present
Al3+ is present
Chemical Reactions involved in it are:
Lake test: AlCl 3 + 3NH4OH NH4Cl + Al(OH)3
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Group IV
Detection of Ni 2+
Test Observation Inference
DMG test: To a small
amount of salt solution,
few drops of NH 4OH is
added along with a few
drops DMG(Dimethyl
Glyoxime)
Rose red coloration or
ppt. is formed.
Ni2+ is present and
confirmed.
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Detection of Zn2+
Test Observation Inference
1) Sodium Hydroxide
test: To the salt soln,
few drops of NaOH are
added.
2) H2S gas test: To the
salt soln, few drops of
NH4OH soln. are added
and then H 2S gas is
passed.
3) Potassium Ferro
cyanide test: To the
sample, few drops of
K4[Fe(CN)6] is added .
White ppt is formed that
is dissolved in excess
NaOH.
White ppt is formed
White ppt is formed of
Zinc Ferro cyanide.
Zn2+ is present
Zn2+ is present
Zn2+ is present
Chemical reaction involved in it is:
NaOH test: ZnCl 2 + NaOH ZnOH +NaCl
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K4[Fe(CN)6] test: ZnCl 2 + K4[Fe(CN)6] Zn[Fe(CN)6]
Detection of Co 2+
Test Inference Observation
Ammonium thio cyanate
ether test: To the salt
soln, crystals of NH 4SCN
are added and 1 ml of
amyl alcohol.
Blue coloration of organic
layer.
Co2+ is present.
Chemical Reactions involved in it are:
Ammonium thiocynate ether test:
CoCl2 + NH4SCN (NH4)2[Co(SCN)4] + 2 NH4Cl.
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Detection of Mn2+
Test Observations Inference
1) Sodium Hydroxide
and Bromine test: To
the salt soln, NaOH soln
is added and well shaken
and then Br 2 water is
added.
2) Lead Peroxide test:
To a black ppt. conc.
HNO3 and lead peroxide
are added. It is boiled,
cooled and allowed tosettle down.
A white ppt. was formed.
But after addition of Br 2
water it turned black or
brown.
Pink colored soln is
observed.
Mn2+ is present
Mn2+ is present.
Chemical reactions involved in it are:
1) NaOH and Br 2 water test: MnCl 2 + 2NaOH Mn(OH)2 + 2NaCl
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Mn(OH)2 + Br2 + H20 MnO(OH)2
2) PbO 2 test: MnS + PbO 2 + HNO3 2HMnO4 + Pb(NO)3 + 2 H20.
Group V
Detection of Sr 2+
Test Observation Inference
1) Ammonium Sulphate
test: To the salt soln, 1
ml of ammonium sulphate
soln is added and
warmed.
2)Flame test: Perform
flame test with original
salt
A white ppt. is formed.
Crimson red flame visible
through blue glass.
Sr 2+ is present
Sr 2+ is present.
Chemical reactions involved in it are
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1) Ammonium Sulphate test: SrCO 3 + 2 CH3COOH (CH3COO)2Sr +
CO2 + H20
(CH3COO)2Sr + (NH 4)SO 4 2CH3COONH4 + SrSO 4
Detection for Ba 2+
Test Observation Inference
1) (NH4)2CO3 test: To a
small quantity of salt
soln, few drops of
NH4OH and (NH 4)2CO3 is
added.
2) K2CrO4 test: To the
salt solution Potassium
chromate, K 2CrO4 is
added.
3) (NH4)2SO 4 test: To a
small of salt soln,
(NH4)2SO4 is added.
A white ppt. soluble in
acetic acid is formed.
A yellow ppt. is formed.
A white ppt. is formed.
Ba2+ is present
Ba2+ is present
Ba2+ is present.
Chemical reactions involved in it are:
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BaC03 + 2CH3COOH (CH3C00)2Ba + CO2 + H2O
1) K2CrO4 test: (CH 3C00)2Ba + K2CrO4 2CH3COOK + Ba2CrO4 + H20.
Detection of Ca 2+
Test Observation Inference
1)Ammonium Oxalate
test: To the salt soln.
add 1-2 ml of ammonium
oxalate and a little
ammonium hydroxide is
added to it.
2) Flame test: Perform
Flame test with the
original salt.
White ppt. is formed.
Brick red flame yellow
through blue glass.
Ca2+ is formed.
Ca2+ is formed.
Chemical reactions involved in it are:
CaCO3 + 2CH3COOH (CH3COO)2Ca + CO2 + H2O
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1) Ammonium Oxalate test:
(CH3COO)2Ca + NH4C2O4 2CH3COONH4 + CaC2O4
Group VI
Detection of Mg 2+
Test Observation Inference
1) Ammonium Phosphate
test: To the salt soln,
some solid NH 4Cl and
NH4OH is added. Then
ammonium phosphate
soln. added.
2)Charcoal cavity test:
Perform charcoal cavity
cobalt nitrate test with
A white ppt. is formed.
A pink mass is obtained.
Mg2+ is present.
Mg2+ is present.
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the salt soln.
Chemical reactions involved in it are:
1) Ammonium phosphate test: MgCl 2 + NH4OH + (NH4)2HPO4
Mg(NH4)PO4 + 2NH4Cl + H20
Detection of Na +
Test Observation Inference
1) Potassium pyro-
antimonate test: To the
salt soln, potassium pyro
antimonite soln is
added.
2)Flame test: Perform
flame test the salt soln.
A white milkiness is
observed.
Persistent golden yellow
flame invisible through
blue glass.
Na+ is present
Na+
is present.
Chemical reactions involved in it are:
Potassium pyro-antimonate test: 2NaCl + K 2H2Sb 207 2KCl +
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Na2H2Sb 207
Detection of K +
Test Observation Inference
1) Sodium Cobalt nitrile
test: To the salt soln
NaOH soln is added and
then freshly prepared
sodium cobalt nitrite
soln is added.
2) Picric acid test: To
the salt soln, picric acid
is added.
3)Flame test: Perform
A yellow ppt. is formed.
Yellow shining crystalline
ppt. is formed.
A pale violet flame is
K+ is present.
K+ is present.
K+ is present.
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flame test with the salt
soln.
observed and it is pink
through the blue glass.
Chemical reactions involved in it are:
1) Sodium cobalt nitrite soln:
3KCl + Na3[Co(NO2)6] 3NaCl + K3[Co(NO2)6]
2) Picric acid test:KCl + C 6H2(NO2)3OH HCl + C6H2(NO2)3OK.