Simple mixture
2Catio n
anio n
Scheme for simple mixture f Solid Part of solid for anion Part of solid
Scheme for anions Test for CO32Solid + dil HCl-------- strong effervescent Solution + BaCl2 ------- white ppt soluble in HCl
Test for SO42Solution + BaCl2 ------- white ppt insoluble in HCl
Test for Cl Solution
+ lead acetate ---- white ppt
[ solid + distilled water]
Scheme for cations Tests for cations on solid for ammonia and colored cations Cu----- blue Fe----- reddish brown Cr------ dark green Co------ pink Ni-------- Green
Test for ammonia (in porcelain dish) Solid + dil. NaOH
ammonia odour
Test for Cupper Soln.+ H2S
black ppt
Soln. + pot.ferrocyanide
chocolate brown
ppt
Test for Cromium Soln + NH4Cl + NH4OH
greenish white ppt
Test for Iron (Fe+3) Soln. + 3 drops conc. HNO3 --- boil-----cool----
NH4SCN---- blood red color----iron present
Test for Cobalt Solid+ 2 ml Amyl alc.+ 1 gm NH4SCN---Shake
----blue color in alcoholic Layer---Cobalt present
Test for Nickel soln + NH4Cl + NH4OH till Amm. odour appear +
Dimethyl glyoxime (DMG)
Rose red ppt
Solubility step Dissolve part of solid to form
(Clear Solution)
soluble
☻Solid + solvent
o Sequence of solvents:
Water [ cold, hot]
dil. HCl [cold, hot]
Conc.
HCl [cold, hot]
Take part of solution then add reagent of gp I If ppt ------add gp reagent on all beaker then filter Stock solution
Residue ppt of gp I
filterate gp II-VI
Group I : Pb , Hg2 ,Ag
+
+2
+2
Soln. + Cold dil HCl ---- white ppt White ppt + 10 ml water, boil and filter
If
soluble Pb+2 insoluble Hg2+2 ,Ag+
Confirmatory tests for Lead soln.+KI------yellow ppt. soln.+ K2CrO4------yellow ppt
Confirmatory tests for Ag+ andHg2+2 Residue + dil NH4OH ------- if
insoluble
soluble Hg2+2
Ag+
For Ag+ Solution+ K2CrO4------ Red ppt
Confirmatory tests for Hg2+2 Residue + aqua regia (3HCl:1HNO3) in porcelain dish----
evaporate till dryness----dissolve residue in few drops of water --add SnCl2 (stannous chloride)----- white---grey ---- black ppt
Group II A (Pb+2, Hg+2, Bi+3, Cu+2, Cd+2) Group II B (As+3, Sb+3 , Sn+2 )
:Add group reagent- 2 ďƒ˜ Soln. (adjusted acidity) + excess H2S 3- Test for complete precipitation: Filter take part of filterate and then add excess of H2S if ppt no complete precipitation so add excess of H2S no ppt complete precipitation
Precipitate Yellow ppt cd+2 or gp II B
Black or brown Bi +3, Cu+2, Hg+2 , Pb+2
If back or brown Small part of residue + 10 ml dil HNO3 + 10 ml dil H2SO4 boil if Soluble Insoluble
Bi+3 or Cu+2 Pb+2 or Hg+2
)Confirmatory tests for Bismuth (Bi+3- 2 Soln+ conc. NH4OH--------white gelatinous ppt
)Confirmatory tests for Cupper (Cu+2 Soln + conc.NH4OH-------blue colour If insoluble Pb+2 or Hg+2 Part of residue + NH4AC
soluble Pb+2 insoluble Hg+2 confirmatory tests as in group I
To differentiate between Cd+2 and gpIIB To part of yellow ppt-----add 8% NaOH + 1 drop of ammonium sulphide (H2O2)warm and shake Soluble Insoluble gp II B Cd+2
)Confirmatory tests for arsenic (As+3 Soln. + Magnesium mixture (Mix of MgCl2 &
NH4OH) --------White ppt
)Confirmatory tests for Stannous (Sn+2 Soln + HgCl2-------white to grey to black ppt
Filterate from gp II must be boiled to expel H2S Test for presence of H2S Paper moistened with lead acetate exposed to vapour of boiled solution if black boil again as H2S is still present
(Gp III (Al , Fe and Cr +3
+3
+3
ďƒ˜Soln. + NH4Cl (solid)----dissolve---- add dil NH4OH till
amm. odour
White gelatinous ppt AL+3
greenish white ppt reddish brown ppt Fe+3
Cr+3 soluble Al+3 or Cr+3
Part of residue + NaOH + H2O2 insoluble
Fe+3
boil
if
Test for Al+3 • Part of solution + NH4Cl ------ boil-----cool----white ppt
Test for Cr+3 To yellow solution, add dil HAC+ 2 drops lead acetate --yellow ppt Test for Fe+3 Part of residue + dil HCl ------ give clear solution Solution + NH4SCN ----- Blood red color
Group IV: Zn , Co and Ni +2
+2
+2
Soln. + NH4Cl (solid)--------dissolve----- add dil
NH4OH till amm. odour --------add excess H2S white ppt Zn+2
Co+2 or Ni+2
Black ppt
Part of residue + 10 ml very dil HCl boil with
stirring
soluble Zn+2
insoluble Co+2 or Ni+2
(Confirmatory tests for Zinc (Zn+2 Soln+ acetic acid+ pot. ferrocyanide------greenish white ppt.
Confirmatory tests for Co+2 or Ni+2 Residue + aqua regia evaporate to dryness then cool and add 5 :ml water and boil------ divide solution into 2 portions Test for Co+2 Test for Ni+2
As mentioned before
Group V: Ca , Ba and Sr +2
+2
+2
Boil filterate from gp IV to expel H2S and to
concentrate the solution Conc. Soln.+ NH4Cl (solid)--------dissolve--- add
Conc.NH4OH till amm. odour --------add solid (NH4)2CO3-----------white ppt. Dissolve ppt in 10 ml dil HAC and divided into 3
portions
Confirmatory tests must be done in the following sequence:
Test for Ba+2: Soln. + dil HAC+ K2CrO4----------yellow ppt
Test for Sr+2: Soln. + (NH4)2SO4--------------white ppt.
Test for Ca+2 Soln. + ammonium oxalate---------white ppt.
ďƒ˜ The filterate from gp V is treated with
ammonium sulphate + ammonium oxalate, heated to boiling . ďƒ˜After allowing standing for 5 minutes it is
filtered and the residue is rejected and divide filterate 3 portions:
Group VI: NH4+, Mg+2, Na+, K
+
Confirmatory tests must be done in the following sequence
Test for Mg+2: o Soln+ NH4Cl (solid)--dissolve-- add dil NH4OH+Na2HPO4 --scratching-------white ppt.
Test for Na+ o Soln + potassium pyroantimonate ----------white ppt
Test for K+ o Soln. + dil HAC+ sodium cobalt nitrite -------yellow ppt