1. Qualitative Inorganic Analysis
By : Tedi Hadiana
SMK Negeri 13 Bandung

2. Separation of cations into groups
I (Silver Groups)
Ag+,Hg+,Pb2+
IIA (Copper Groups)
Cu2+,Hg2+,Cd2+,Bi3+,Pb2+
IIB (Arsenic Groups)
As3+,Sb3+,Sn2+
III (Iron Groups)
Al3+,Fe3+,Cr3+,Mn2+
IV (Zinc Groups)
Ni2+,Co2+,Zn2+,Mn2+
V (Calcium Groups)
Ca2+,Sr2+,Ba2+
VI (Residue Groups)
Na+,K+,Mg2+,NH4+

3. Separation of cations into groups
Sample Solution
Groups I (Residue)
Filtrate
Groups II (Residue)
Groups IIA (Residue)
Groups IIB (Filtrate)
Groups III (Residue)
Groups IV (Residue)
Groups VI
Groups V (Residue)
+ HCl 6N
+ H2O210%, heat
+ I2 , pH 0,5
+ H2S
H2S removed (heat)
+ NH4Cl + NH4OH
+ (NH4)2Sx
+ NH4Cl + NH4OH + (NH4)2S
+ NH4Cl + (NH4)2CO3

4. Separation and Identification of Groups 1
Residue Groups I may contain:
AgCl(white), Hg2Cl2(white), PbCl2(white)
Filtrate may contain : PbCl2
Identification:
Cool a portion of the solution  white crystalline residu of PbCl2
Add 1 M K2CrO4 solution  yellow residue of PbCrO4, soluble in NaOH solution
Add dilute 2 M H2SO4 (+alcohol)  white residue of PbSO4 soluble in NH4OAc solution
Filtrate may contain : [Ag(NH3)2]+
Acidity with dilute HNO3  white residue of AgCl
Add a few drops of KI solution  pale yellow residue of AgI
Residue may contain : AgCl, Hg2Cl2
Residue : Hg2Cl2
If black, consists of Hg(NH2)Cl + Hg.
Hg22+ present
Wash the residu with 2 mL of 2M HCl, then 2-3 times with 1 mL portions of cold water then add 2 mL hot water and heating for 2-3 minutes
Pour 1 mL dilute 2 M NH4OH solution

5. Separation and Identification of Groups 1
Filtrate may contain : Hg(NO3)2
Identification:
Place 1 drop filtrate upon SnCl2 paper  greyish-black spot of Hg
Place drop filtrate on a glossy copper surface  silverish spot of Hg
Add 1 mL aqua regia (HNO3 : HCl = 1:3)
and heat cautiously until the mixture is dry
Then add 1 mL 2 M HNO3 (centrifuge)
Residue : Hg2Cl2
If black, consists of Hg(NH2)Cl + Hg.
Hg22+ present

6. Separation and Identification of Groups 2A
Residue Groups II A may contain :
HgS(black), CuS(black), CdS(yellow), Bi2S3{black-brown), PbS (black)
Filtrate may contain : Cu, Cd, Bi, Pb
Residue may contain : PbSO4
Wash the residue with water to be free of chloride (2-3 times)
add 2 mL dilute HNO3 1:1, boil gently for 2-3 minutes (centrifuge)
Residue may contain: HgS
Wash the residue with aquadest (2-3 times)
Add 1 mL aqua regia and heat cautiously until the mixture in dry
Add 1 mL water, stir
Identification, see Hg+ of groups 1
Filtrate may contain : Cu ,Cd ,Bi
Add 5 drops of H2SO4 concentrated and heat cautiously until the mixture is dry
Add 1 mL water (centrifuge)
Filtrate my contain : Pb2+
Identification:
Add a few drop of 1 M K2CrO4 solution  yellow residue of PbCrO4
Dissolved residue with 10 drops 2M NH4OAc

7. Separation and Identification of Groups 2A
Filtrate may contain : [Cu(NH3)4]2+ and [Cd(NH3)4]2+
Identification:
If deep blue in colour  Cu2+ present
Confirm Cu2+ by acidifying a portion of the filtrate with dilute 2M HCl and add K4[Fe(CN)6]  reddish-brown residue of Cu2Fe(CN)6
Drop of the filtrate upon filter paper and give a NH3 vapor  blue spot
Pour the filtrate on H2S liquid (If Cu present, add 2 M KCN solution until blue color is discharged)  yellow residue of CdS
Filtrate may contain : Cu ,Cd ,Bi
Residue may contain : Bi(OH)3
Wash the residue with water dissolve in the minimum volume of 2M HCl solution
Pour in to SnCl2 solution and more of 2M NaOH  black brown residue of Bi
Dissolve a little residue in drop of dilute 2 M NaOAc then place upon filter paper moistened with cinchonine-KI reagent  orange-red spot
Add 6 M NH4OH solution (centrifuge)

8. Separation and Identification of Groups 2 B
Filtrate Groups II B may contain :
(NH4)3AsS4, (NH4)2SbS4, (NH4)2SnS3
Filtrate may contain : SbCl3 and SnCl4
Add concentrated 6 M HCl dropwise
Warm gently for 3 minutes (centrifuge)
Residue may contain : As2S5
Wash the residue with water (1-2 times)
Dissolve residue with 1 mL of 6M NaOH solution  Filtrate
Identification:
Add 6 M NaOH solution and add 2 piece metallic Aluminium then gases identification with HgCl2  grey spot from Hg
Add H2O2 3% solution and warm for a few minutes oxidize arsenit to arsenat
2 drops of the filtrate + 2 drops 2M HCl solution and add Mg-mixture  white residue of MgNH4AsO4
2 drops of the filtrate with HNO3 concentrated and add 10 drops of molibdat reagent  yellow residue of NH4-arsenat molibdat
Residue Group II B may contain :
As2S5 (yellow), Sb2S5 (orange), SnS2 (yellow)
Wash the residue with aquadest (2-3 times)
Add 6 M HCl and warm gently for 3 minutes (centrifuge)

9. Separation and Identification of Groups 2 B
Filtrate may contain : SbCl2 and SnCl4
Filtrate may contain : Sb3+
Identification:
To 2 drops of the filtrate add KNO2 (solid) mixing until gas become steam and then 2 drops of RhodamineB reagent (red color)  violet solution
Filtrate : Sn2+
Dissolve the filtrate with HgCl2 5 % solution  white residue of Hg2Cl2 or grey residue of Hg (Sn present)
Place 1 drop the filtrate upon cacothilin paper  red or purple spot (Sn present)
Add metallic iron in to the filtrate
Warm gently for 3 minutes
Add 10 mL of water (centrifuge)

10. Separation and Identification of Groups 3
Residue Groups III may contain :
Fe(OH)3 (brown), Al(OH)3 (white), Cr(OH)3 (green), MnO2.xH2O (brown)
Filtrate may contain : NaAlO2, Na2CrO4
Wash the residue with a little NH4NO3 solution (2-3 times)
Add 1,5 mL of 2M NaOH and 0.5 mL 6% H2O2
Boil gently until the evolution of O2 ceases (2-3 minutes)-(centrifuge)
Residue may contain : Fe(OH)3, MnO2.xH2O
Filtrate may contain : Fe3+
Identification:
To the filtrate add a few drops of 2 M KSCN solution  deep red colouration (Fe present)
To the filtrate add K4[Fe(CN)4] solution  blue residue (Fe present)
Wash the residue with 1 mL of NH4NO3 solution.
Dissolve residue in to 5 drops of HCl concentrated then dilute solution until 1 mL
Filtrate may contain : Mn2+
To the filtrate add 5 drops of 6 M HNO3 solution and a few drops of NaBiO3/KIO4/PbO2 warm for a few minutes  violet solution (Mn present)
Heat 2 drops of the filtrate until the mixture is dry add Na2CO3 solid and KClO3 solid then melted  green solution of K2MnO4 (Mn present)

11. Separation and Identification of Groups 3
Filtrate may contain : NaAlO2, Na2CrO4
Acidify with HOAc until just neutral (test with litmus paper) (centrifuge)
Filtrate may contain : Al3+
Identification:
To the filtrate add 2 drops of 6M NH4OH solution  white residue of Al(OH)3
To 5 drops of the filtrate add 2 drops of 6M NH4OAc solution and 3 drops of the aluminon reagent then heat for 5 minutes. Add (NH4)2CO3 until just alkaline and add 3 drops later red residue
Filtrate may contain : Cr3+
Acidity with acetic acid and add Pb(OAc)2 solution  yellow residue of PbCrO4
To 5 drops of the filtrate add 2 drops of AgNO3 solution  red residue of Ag2CrO4
Residue may contain : Al(OH)3
Filtrate may contain : Na2CrO4
Wash the residue with a few water
Dissolve with a few 2M HCl solution

12. Separation and Identification of Groups 4
Residue Groups IV may contain :
CoS (black), NiS (black), MnS (brown), ZnS (putih)
Filtrate may contain : ZnCl2, MnCl2
Wash the residue with a little NH4OH solution (2-3 times)
Add 1 mL water and 6 drop 2M HCl solution
If black Residue may contain : CoS, NiS
Filtrate may contain : Ni2+
Identification:
Add 5 drop NH4Cl solution + NH4OH solution (until alkaline) + DMG reagent  red residue
Wash the residue with 1 mL of acetic acid solution.
Dissolve the residue in 1 mL of aqua regia and heat cautiously until the mixture is dry. Then add 1 mL 2M HCl solution
Filtrate may contain : Co2+
Add 0.5 mL amyl alcohol, 0.5 g solid KSCN and shake well  amyl alcohol layer coloured blue
Add 5 drop 2M HCl + -nitroso -naphtol + chloroform  Chloroform layer coloured red

13. Separation and Identification of Groups 4
Filtrate may contain : ZnCl2, MnCl2
Heat until H2S removed, Add 10 drops 6M NaOH + H2O2 . Boil gently until the evolution of O2 ceases (2-3 minutes)
Residue may contain : MnO2
Filtrate may contain : Na2ZnO2
Identification:
Acidity with acetic acid and pass H2S  white residue of ZnS
Acidity with H2SO4, add 0,5mL of 0,1% CuSO4 solution and 1 mL (NH4)2[Hg(CNS)4] reagent (stir)  violet residue
Acidity with H2SO4, add K4[Fe(CN)6]  white residue
Wash the residue with 1 mL of water
Dissolve residue in to
5 drops of HCl concentrated
then dilute solution until 1 mL
Filtrate may contain : Mn2+
Identification:
To the filtrate add 5 drops of 6 M HNO3 solution and a few drops of NaBiO3/KIO4/PbO2 warm for a few minutes  violet solution

14. Separation and Identification of Groups 5
Residue Groups V may contain :
CaCO3 (white), BaCO3 (white), SrCO3 (white)
Filtrate may contain : Ca2+, Sr2+
Wash the residue with aquadest (2-3 times)
Dissolved residue with few hot 2M acetic acid solution
Then add 3 drop NH4OAc + K2CrO4
Residue may contain : BaCrO4
Identification :
Dissolve the residue in a little concentrated HCl (flame test)  Green (yellowish-green) flame
Filtrate may contain : Ba2+
Identification:
add a few drops of 2 M H2SO4 solution  white residue of BaSO4
Wash the residue with hot water
Dissolve residue in 1mL of hot 2M HCl solution
Residue may contain :
SrSO4
Filtrate add 2 mL saturated (NH4)SO4 solution, followed by 0.2 g Na2S2O4 heat in a beaker of boiling water for 5 minute
Filtrate may contain :
Ca2+

15. Separation and Identification of Groups 5
Residue may contain :
SrSO4
Identification :
Wash with a little water, then dry the residue.
With a few drops concentrated HCl apply the flame test  crimson flame (Sr present)
Filtrate may contain : Ca2+
Add a little (NH4)2C2O4 solution , 2mL 2M acetic acid and warm on a water bath  White residue of CaC2O4

16. Separation and Identification of Groups 6
Filtrate Groups V I may contain :
Mg2+, Na+, K+
Filtrate may contain : Mg2+
Identification :
add 2 drops of magneson reagent, + NaOH solution until alkaline  blue residue
Add 2 drops 2M NH4Cl + NH4OH +Na2HPO4 solution  white residue of MgNH4PO4
Put filtrate in evaporation crucible
It is evaporated to dryness and heated until all the ammonium salts have been volatilized
The dry residue is extracted with water
Filtrate may contain : Na+
Add a little Uranyl zink acetate reagent, shake and allow to stand for a few minutes  yellow crystalline residu
Filtrate may contain : K2+
Add a little Sodium hexanitrito-cobaltate(III) solution and drops dilute acetic acid. Stir and allow to stand for 1-2 minutes  yellow residue of K2[Co(NO2)6]

17. Filtrate : Soda Extract
Separation and Identification of Sulphates, Sulphites, Oxalates, Chromates, Flourides
Filtrate : Soda Extract
Acidity 1 mL of filtrate with 1 M HCl solution
Add Cd(NO3)2 solution to discharge sulphides ions
Filtrate
Residue : CdS, S
Identification :
CdS  yellow residue
S  white residue (from Na2S2O3)
Add BaCl2 solution
Residue : SO42-
Identification :
BaSO4  white residue
There is SO42- present
Filtrate
Add Br2 solution shake well until the filtrate is not decolourized
Residue : SO32- and S2O32-
Identification :
BaSO4  white residue
There is SO32- or S2O32- present
Filtrate

18. Residue : H2CrO4/H2Cr2O7, HF and H2C2O4
Separation and Identification of Sulphades, Sulphites, Oxalates, Chromates, Flourides
Filtrate
Add NaOAc solution (centrifuge)
Residue : H2CrO4/H2Cr2O7, HF and H2C2O4
Identification :
BaCrO4  yellow residue (there is H2CrO4 or H2Cr2O7 present)
BaF2  white (if there have a lot of HF and H2C2O4 )
Filtrate :
Identification :
Add CaCl2  white residue of CaC2O4 and white residue of CaF2 (centrifuge)
Place the residue in 2 M HOAc solution and add 1 drops of 0,2 M KMnO4 shake and warming (If KMnO4 is bleached, add KMnO4 solution in excess until the colour is constant)
If all of the residue is dissolved  just H2C2O4 present
If there is still the residue  H2C2O4 and HF present
If adding 1 drops of 0,2 M KMnO4 is not decolourized  CaF2 residue and just HF present

19. Separation and Identification of Sulphades, Sulphites, Oxalates, Chromates, Flourides
Residue may contain :
AgCl (white), AgSCN (white), AgBr (white-yellow), AgI (yellow)
If there is SCN-, AgSCN must be removed first as follows : Add 1mL of HNO3 concentrate and steam solution until almost dry (repeat once more until oxidation AgSCN has finished)
Wash the residue has been free AgSCN with 1 mL of H2O and 5 drops of 6 M HNO3 until free of Ag+
Add 10 drops of 1 M (NH4)2CO3 (centrifuge)
Filtrate : Ag(NH3)2+, Cl-
Identification :
At a part of filtrate add 1 drops 1 M KBr  yellowish white residu of AgBr , Cl- present
Acidity with 6 M HNO3  white residue of AgCl, Cl- present
Residue may contain : AgBr, Agl

20. Residue may contain : AgBr, Agl
Separation and Identification of Sulphades, Sulphites, Oxalates, Chromates, Flourides
Residue may contain : AgBr, Agl
Add a few of Zn solid and 1 mL 2M H2SO4 (by reduce coming about HBr and HI) centrifuge
Identification filtrate about Iodide :
To the filtrate add 1drop of 0,1 M FeCl3 (1:1) and place 1 drop of solution upon starch paper  blue spot of I-
If Iodide is present must be remove first as follows :
A part of the filtrate adding 0,1 FeCl3 (1:1) and boil gently until all iodide are volatilized (test with starch paper)
3. For the filtrate of free from Iodide add 3 drops of 0,1 M KMnO4 and 3 drops of 3 M H2SO4 then shake well. KMnO4 excess must be remove with 10% H2O2 Add CHCl3  CHCl3 layer coloured brown  Bromide present

21. Preliminary Test For Solid Samples
Generally test
Appearance :
Observe whether it is
crystalline or powder
magnetic
possesses any characteristic odour or colour
Flame test
Test with H2SO4 (dilute and concentrated)
Test with NaOH
Test with KHSO4
Solubility test

22. Chemical substance type
Solid
Liquid
Gas
Crystalline
Powder

23. Difference of Crystalline and Powder type
Very small particle size
(fine grained)
Large particle size than powder
Memiliki kilap saat terkena cahaya
Tidak memiliki kilap
Ex. : CaCO3, MnSO4,
Amyllum, etc
Ex. : NaCl, Na2S2O3,
CuSO4, K2Cr2O7, etc

24. Some of commonly occurring coloured compound are listed below:
Chemical Compound
Red
As2S2, HgI2, Sb2S3, Cu2O, K3[Fe(CN)6], Fe(SCN)3, etc
Orange-red
K2Cr2O7
Reddish-purple
KMnO4
Pink
Hydrated salts of Manganese and of Cobalt
Yellow
K2CrO4, K4[Fe(CN)6], CdS, Fe(III), PbI2, etc
Green
Cr(III), Fe(II), Ni(II), Cr2O3, K2MnO4, etc
Blue
Cu(II), anhydrous cobalt salts
Brown
Fe2O3, Fe(OH)3, MnO2, etc
Black
PbS, FeS, NiS, CuS, HgS, C, etc

25. Hygroscopis Properties
Some chemical substance can easily catch water from air  Chemical substance wet looks
Generally, chloride salt have hygroscopis properties. Example : CaCl2, MgCl2, CoCl2 , FeCl3, MnCl2, etc
Other example : NaOH, KOH, etc

26. Some of commonly occurring odoured compound are listed below:
Odors
Some of commonly occurring odoured compound are listed below:
Odors
Chemical Compound
Ammonia
Ammonium salt
Bad smell (H2S)
Sulfide salt
Reddish-purple
KMnO4
Pink
Hydrated salts of Manganese and of Cobalt
Yellow
K2CrO4, K4[Fe(CN)6], CdS, Fe(III), PbI2, etc
Green
Cr(III), Fe(II), Ni(II), Cr2O3, K2MnO4, etc
Blue
Cu(II), anhydrous cobalt salts
Brown
Fe2O3, Fe(OH)3, MnO2, etc
Black
PbS, FeS, NiS, CuS, HgS, C, etc