SALT ANALYSIS

TESTS FOR ANIONS

(1) CARBONATE ION (CO32--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample in U tube + Dil. H2SO4 Brisk effervences (CO2) CO32—may be
2 Pass above gas in lime water Turns milky (CaCO3) CO32— confirmed
3 Sample in test tube + MgSO4 White ppt. (MgCO3) CO32— confirmed
(2) CHLORIDE ION (Cl--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat Colourless gas with Cl—may be
pungent smell (HCl)
3 Bring a rod dipped in NH4OH at mouth White fumes (NH4Cl) Cl— confirmed
of above test tube
4 Sample + Dil. HNO3 + heat + cool + White ppt.(AgCl) soluble Cl— confirmed
AgNO3 in NH4OH
5 Chromyl Chloride test
Sample in U tube + solid K2Cr2O7 + conc. Red brown gas (CrO2Cl2)
H2SO4+ Heat + NaOH in side tube Yellow soln. (Na2CrO4)
Add acetic acid and lead acetate in side Yellow ppt. (PbCrO4) Cl— confirmed
tube
(3) BROMIDE ION (Br--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat Brown gas Br—or NO3-- may
be
3 Add a paper ball or copper turnings to Fumes decrease Br—may be
above solution
4 Sample + Dil. HNO3 + heat + cool + Pale yellow ppt.(AgBr) Br— confirmed
AgNO3 partly soluble in NH4OH
5 Layer test Orange layer(Br2) Br— confirmed
Sample + water + Dil. HCl + CS2 +
chlorine water + shake
(4) IODIDE ION (I--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat Violet gas (I2) I--may be
3 Sample + Dil. HNO3 + heat + cool + Bright yellow ppt.(AgI) I-- confirmed
AgNO3 insoluble in NH4OH
4 Layer test Violet layer(I2) I-- confirmed
Sample + water + Dil. HCl + CS2 +
chlorine water + shake
(5) NITRATE ION (NO3--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat Brown gas Br—or NO3-- may
be
3 Add a paper ball or copper turnings to Fumes increase NO3-- may be
above solution
4 Ring test Brown ring NO3-- confirmed
Sample + fresh FesO4 + Conc. H2SO4 [Fe(NO)(H2O)5]SO4
along the sides of test tube
(6) ACETATE ION (CH3COO--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat Colourless gas with smell CH3COO--may be
of vinegar
3 Sample on a watch glass + solid oxalic Strong smell of vinegar CH3COO--may be
acid + 2 drops water + rub with finger +
smell
4 Sample + water + neutral FeCl3 Red solution
Divide into 2 parts
Frist part + DilHCl Red colour disappears CH3COO--
Second part + water + Boil Red brown ppt. confirmed
5 Ester test Fruity smell CH3COO--may be
Sample + Conc. H2SO4+ Heat + ethyl
alcohol + shake and pour the mixture
to a beaker filled with water and smell
(7) OXALATE ION (C2O42--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat Colourless gas which turn C2O42--may be
lime water milky
3 Sample + water + acetic acid + Heat + White ppt (CaC2O4)
CaCl2
 Add Dil HNO3 + heat ppt dissolves C2O42-- confirmed
4 Sample + Dil. H2SO4 + heat + KMnO4 Pink colour of KMnO4 C2O42-- confirmed
disappears

(8) SULPHATE ION (SO42--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat No reaction Conc. group
absent
3 Sample + water + BaCl2 White ppt (BaSO4) SO42-- confirmed
4 Sample + water + Lead acetate White ppt (PbSO4) SO42-- confirmed

(9) PHOSPHATE ION(PO43--)

S.NO EXPERIMENT OBSERVATION INFERRENCE

.
1 Sample + Dil. H2SO4 No reaction Dilute group
absent
2 Sample + Conc. H2SO4+ Heat No reaction Conc. group
absent
3 Sample + conc. HNO3 + boil + Deep yellow PO43--- confirmed
Ammonium molybdate soln. in excess ppt(Ammonium
+ boil phosphomolybdate)
4 Solid NH4Cl + MgCl2 + Boil + Cool + White ppt (MgNH4PO4) PO43--- confirmed
NH4OH till strong smell of ammonia is
obtained + sample

TESTS FOR CATIONS

(1) AMMONIUM ION (NH4+)

S.NO. EXPERIMENT OBSERVATION INFERRENCE

1 Sample in a U tube +NaOH + Heat Colourless gas with smell NH4+ may be
of ammonia( NH3)
2 Bring a rod dipped in DilHCl at mouth White fumes (NH4Cl) NH4+ confirmed
of above tube
3 Take Nesslers reagent in side tube of Brown ppt (NH2.HgO.HgI) NH4+ confirmed
above U tube and allow the gas to
pass
(1) LEAD ION (Pb2+)

S.NO. EXPERIMENT OBSERVATION INFERRENCE

1 Original solution + DilHCl White ppt (PbCl2) Pb2+ may be
2 Above ppt + water + divide into 2
parts
First part + KI Yellow ppt (PbI)
Second part + K2CrO4 Yellow ppt (PbCrO4) Pb2+ confirmed

(2) COPPER ION(Cu2+)

S.NO. EXPERIMENT OBSERVATION INFERRENCE

1 Original solution + Dil. HCl No reaction I group absent
2 Above solution + Na2S soln. or H2S gas Black ppt (CuS) Cu2+ may be
3 Heat above ppt with conc HNO3 + Blue soln.
NH4OH in excess
4 Above blue soln. + K4[Fe(CN)6] Chocolate brown ppt Cu2+ confirmed
(Cu2[Fe(CN)6])
5 Blue soln + acetic acid + KI White ppt in brown soln. Cu2+ confirmed
(Cu2I2)