Analysis of Group Iii Cations
ANALYSIS OF GROUP III CATIONS
Precipitation of Group III Cations and Separation into Subgroups
Analysis of Subgroup A of Group III Cations
Analysis of Subgroup B of Group III Cations (PART 1)
Analysis of Subgroup B of Group III Cations (PART 2)
-----------------------
Use decantate from group II cations
Precipitate
Decantate
Consider as Group IIIB.
Consider as Group IIIA.
Centrifuge and separate.
Add 10 drops of 1M HCl.
Wash with few drops of H2O.
Precipitate
Decantate
Centrifuge and separate.
Proceed to Group IV Analysis.
NO
YES
Does precipitate occur?
Add 1 ml of NH3 and heat in water bath for 5 mins.
Add 1 ml of 5% thioacetamide and heat in water bath for 5 mins.
Use Group IIIA precipitate.
Add 1 drop of
Dimethylglyoxime.
Discard.
Dilute to 1 ml and divide into 3.
Boil solution and add 6M NH3 until slightly basic to litmus.
Decantate
Centrifuge and separate.
Precipitate
Discard.
Add 1 drop of 16M HNO3 and heat in water bath for 5 mins.
Wash with 4 drops of 1M HCl.
Add 3 drops 12M HCl.
Precipitate
Decantate
Centrifuge and separate.
Let stand for 1 min.
Acidify with 6M HOAc and add several KNO2 crystals
Acidify with 1 M HCl and add several NH4CNS crystals.
Warm mixture.
Add equal volume of acetone or ethanol and agitate the mixture afterwards.
Formation of yellow precipitate indicates presence of Co3+.
Formation of bright reddish pink precipitate means presence of Ni2+.
Formation of blue colored solution shows presence of Co2+.
Use Group IIIB decantate.
Add 1 ml of 4M HNO3 and evaporate.
Dissolve residue in 1 ml water and place it in a test tube.
Add 4M NaOH until precipitate forms. Add another 10 drops of NaOH.
Add 6 drops of 3% H2O2 and heat in water bath for 5 mins.
Precipitate
Decantate
Centrifuge and separate.
Proceed to Analysis of Group IIIB (Part 2).
Wash with 10 drops of H2O and add 1 drop of
Precipitation of Group III Cations and Separation into Subgroups
Analysis of Subgroup A of Group III Cations
Analysis of Subgroup B of Group III Cations (PART 1)
Analysis of Subgroup B of Group III Cations (PART 2)
-----------------------
Use decantate from group II cations
Precipitate
Decantate
Consider as Group IIIB.
Consider as Group IIIA.
Centrifuge and separate.
Add 10 drops of 1M HCl.
Wash with few drops of H2O.
Precipitate
Decantate
Centrifuge and separate.
Proceed to Group IV Analysis.
NO
YES
Does precipitate occur?
Add 1 ml of NH3 and heat in water bath for 5 mins.
Add 1 ml of 5% thioacetamide and heat in water bath for 5 mins.
Use Group IIIA precipitate.
Add 1 drop of
Dimethylglyoxime.
Discard.
Dilute to 1 ml and divide into 3.
Boil solution and add 6M NH3 until slightly basic to litmus.
Decantate
Centrifuge and separate.
Precipitate
Discard.
Add 1 drop of 16M HNO3 and heat in water bath for 5 mins.
Wash with 4 drops of 1M HCl.
Add 3 drops 12M HCl.
Precipitate
Decantate
Centrifuge and separate.
Let stand for 1 min.
Acidify with 6M HOAc and add several KNO2 crystals
Acidify with 1 M HCl and add several NH4CNS crystals.
Warm mixture.
Add equal volume of acetone or ethanol and agitate the mixture afterwards.
Formation of yellow precipitate indicates presence of Co3+.
Formation of bright reddish pink precipitate means presence of Ni2+.
Formation of blue colored solution shows presence of Co2+.
Use Group IIIB decantate.
Add 1 ml of 4M HNO3 and evaporate.
Dissolve residue in 1 ml water and place it in a test tube.
Add 4M NaOH until precipitate forms. Add another 10 drops of NaOH.
Add 6 drops of 3% H2O2 and heat in water bath for 5 mins.
Precipitate
Decantate
Centrifuge and separate.
Proceed to Analysis of Group IIIB (Part 2).
Wash with 10 drops of H2O and add 1 drop of