Tips on Inorganic Chemistry:Practicals for AIEEE- II
in AIEEE, IIT-JEE, Inorganic chemistry on Monday, May 18, 2009
FOR CATIONS
A)Group reagent: Hydrochloric acid, hydrogen sulphide, ammonium sulphide and ammonium carbonate.
| Group | Group reagent | Basic Radical | Composition and Colour of Precipitate |
| 1 | dil. HCl | Ag+ | AgCl; White |
| Pb2+ | PbCl2; White | ||
| Hg22+ | Hg2Cl2; White | ||
| 2 | H2S | Hg2+ | HgS; Black |
| Pb2+ | PbS: Black | ||
| Bi3+ | Bi2S3; Black | ||
| Cu2+ | CuS; Black | ||
| Cd2+ | CdS; Yellow | ||
| As3+ | As2S3; Yellow | ||
| Sb3+ | Sb2S3; Orange | ||
| Sn2+ | SnS; Brown | ||
| Sn4+ | SnS2; Yellow | ||
| 3. | NH4OH in presence of NH4Cl | Fe3+ | Fe(OH)3; Reddish brown |
| Cr3+ | Cr(OH)3; Green | ||
| Al3+ | Al(OH)3; White | ||
| 4. | H2S in presence of NH4OH | Zn2+ | ZnS; Greenish White |
| Mn2+ | MnS; Buff | ||
| Co2+ | CoS; Black | ||
| Ni2+ | NiS; Black | ||
| 5 | (NH4)2CO3 in presence of NH4OH | Ba2+ | BaCO3; White |
| Sr2+ | SrCO3; White | ||
| Ca2+ | CaCO3; White | ||
| 6 | Na2HPO4 | Mg2+ | Mg(NH4)PO4; White |
| 7 | NaOH | NH4+ | Ammonia gas is evolved |
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