Qualitative analysis of Acid Radicals (Anions)
1st Group
2nd Group
3rd Group
Dil. H2SO4 Test (CO32-, S2-, SO32-, NO2-)
Conc. H2SO4 Test(Cl-, Br -, I-, NO3-, C2O42-,
CH3COO-
Independent Radicals(SO42-, PO43-)
S.No.
EXPERIMENT
OBSERVATION
INFERENCE
1.
To the salt dil. H2SO4 was added
Brisk Effervescences due to CO2
CO3-2 may be present
Confirmatory Test For Carbonate:
1. Pass the CO2 gas evolved through lime water.
2. To the salt solution add magnesium sulphate solution.
Lime water turns milky
White Ppt.
CO3-2 confirmed
CO3-2 confirmed
2.
To the salt dil. H2SO4 was added
Rotten egg smelling gas (H2S) which turns lead acetate paper
black
S2- may be present
Confirmatory Test For sulphide:
1. To the salt solution add acetic acid and lead acetate sol.
2. To the salt solution add sodium nitroprusside solution.
Black Ppt.
A purple or violet colouration
S2- confirmed
S2- confirmed
3.
To the salt dil. H2SO4 was added
Burning sulphur smelling gas which turns potassium dichromate
paper green
SO32- may be present
Confirmatory Test For sulphite:
1. To the salt solution add BaCl2 solution.
2. To the salt solution add few drops of KMnO4.
White ppt soluble in dil. HCl
Pink colour disappears.
SO32- confirmed
SO32- confirmed
4.
To the salt dil. H2SO4 was added
Reddish brown gas which turns ferrous sulphate paper black
NO2- may be present
Confirmatory Test For nitrite:
1. To the salt solution add acetic acid and ferrous sulphate solution.
2. To the salt solution add few drops of KMnO4.
Dark brown or black colour
Pink colour disappears.
NO2- confirmed
NO2- confirmed
5.
To the salt conc. H2SO4 was added
Colourless gas with pungent smell
Cl- may be present
Confirmatory Test For chloride:
1. To the salt solution add dil. HNO3 and AgNO3 solution.
White ppt soluble in excess of NH4OH.
Cl- confirmed
6.
To the salt conc. H2SO4 was added
Reddish brown vapours
Br- may be present
Confirmatory Test For bromide:
1. To the salt solution add dil. HNO3 and AgNO3 solution.
A light yellow ppt partially soluble in excess of NH4OH.
Br- confirmed
7.
To the salt conc. H2SO4 was added
Violet vapours
I- may be present
Confirmatory Test For iodide:
1. To the salt solution add dil. HNO3 and AgNO3 solution.
A yellow ppt in soluble in excess of NH4OH.
I- confirmed
8.
To the salt conc. H2SO4 was added
A coloureless and odourless gas
C2O42- may be present
Confirmatory test for oxalate:
a) To the salt solution add acetic acid and calcium chloride solution
b) To the salt solution add dil. H2SO4, warm and add 2-3 drops of KMnO4 solution
White ppt.
Pink colour is discharged.
C2O42- confirmed
C2O42- confirmed
9.
To the salt conc. H2SO4 was added
Colourless vapour with vinegar smell
CH3COO- may be present
Confirmatory test for acetate ion:
a) To the salt add dil. H2SO4 and warm. Add 4-5 drops of ethyl alcohol
b) To the solid salt add oxalic acid and 2-3 drops of water. Rub the mixture.
Fruity smell
Vinegar like smell
CH3COO- ion confirmed
CH3COO- ion confirmed
8.
To the salt a piece of filter paper and conc. H2SO4 was added and the mixture was heated
Reddish brown gas evolved
NO3- may be present
Confirmatory Test For nitrate:
1. To the salt solution add freshly prepared FeSO4 solution & then add conc. H2SO4 slowly
along the side of the test tube
2. To the salt add copper chips and conc. H2SO4 and heated
A dark brown ring is formed at the junction of the layers of the
two liquids.
Reddish brown gas evolved
NO3- confirmed
NO3- confirmed
9.
Confirmatory Test For Sulphate:
To the salt solution dil. HCl and BaCl2 were added
White ppt. insoluble in dil. HCl
SO42- confirmed
10.
Confirmatory Test For Phosphate:
To the salt solution conc. HNO3 and ammonium molybdate solution were added
Yellow ppt.
PO43- confirmed
