Inorganic Group Analysis (Qualitative Analysis of Inorganic Radicals) :
Cation (Basic Radical) Analysis
| Group | Radicals (Cations) | Group Reagent | Confirmatory Test | Observation | Chemical Equation (Example) |
|---|
| Group I | Pb²⁺, Ag⁺, Hg₂²⁺ | Dil. HCl | Pb²⁺: K₂Cr₂O₇ Test | Yellow ppt. of PbCrO₄ | Pb²⁺ + Cr₂O₇²⁻ → PbCrO₄↓ |
| | | Ag⁺: NH₃ Test | White ppt. dissolves in excess NH₃ | AgCl + 2NH₃ → [Ag(NH₃)₂]⁺ |
| Group II | Cu²⁺, Pb²⁺, Cd²⁺, Hg²⁺ | H₂S in dil. HCl | Cu²⁺: Ammonia Test | Blue solution | Cu²⁺ + 4NH₃ → [Cu(NH₃)₄]²⁺ |
| | | Pb²⁺: K₂Cr₂O₇ Test | Yellow ppt. of PbCrO₄ | Pb²⁺ + Cr₂O₇²⁻ → PbCrO₄↓ |
| Group III | Fe³⁺, Al³⁺, Cr³⁺ | NH₄OH + NH₄Cl | Fe³⁺: K₄[Fe(CN)₆] Test | Prussian blue ppt. | Fe³⁺ + [Fe(CN)₆]⁴⁻ → Fe₄[Fe(CN)₆]₃↓ |
| | | Al³⁺: Aluminon Test | Red lake formation | Al³⁺ + Aluminon → Red complex |
| Group IV | Zn²⁺, Mn²⁺, Co²⁺, Ni²⁺ | H₂S in NH₄OH | Zn²⁺: NaOH Test | White ppt. dissolves in excess | Zn²⁺ + 2OH⁻ → Zn(OH)₂↓ |
| | | Mn²⁺: Ammonium Peroxodisulfate Test | Pink color | Mn²⁺ + (NH₄)₂S₂O₈ → MnO₄⁻ (pink) |
| Group V | Ca²⁺, Sr²⁺, Ba²⁺ | (NH₄)₂CO₃ | Ca²⁺: Flame Test | Brick-red flame | Ca²⁺ → Brick-red flame |
| | | Ba²⁺: K₂Cr₂O₇ Test | Yellow ppt. | Ba²⁺ + Cr₂O₇²⁻ → BaCrO₄↓ |
| Group VI | Mg²⁺ | (NH₄)₂HPO₄ | Mg²⁺: Magneson Test | Blue ppt. | Mg²⁺ + NH₄HPO₄ → MgNH₄PO₄↓ |
| Soluble Group | Na⁺, K⁺, NH₄⁺ | No ppt. formed | Na⁺: Flame Test | Golden-yellow flame | Na⁺ → Golden-yellow flame |
| | | NH₄⁺: Nessler’s Test | Brown ppt. | NH₄⁺ + Nessler’s Reagent → Brown complex |
Anion (Acid Radical) Analysis
| Group | Radicals (Anions) | Test Name | Reagent Used | Observation | Chemical Equation (Example) |
|---|
| Dil. H₂SO₄ Group | CO₃²⁻, SO₃²⁻, S²⁻ | Effervescence Test | Dil. H₂SO₄ | CO₂ gas with effervescence | CO₃²⁻ + 2H⁺ → CO₂↑ + H₂O |
| | Lead Acetate Test | Pb(CH₃COO)₂ | Black ppt. (for S²⁻) | Pb²⁺ + S²⁻ → PbS↓ (black) |
| Conc. H₂SO₄ Group | Cl⁻, Br⁻, I⁻, NO₃⁻ | Silver Nitrate Test | AgNO₃ | White ppt. (Cl⁻), Pale yellow ppt. (Br⁻), Yellow ppt. (I⁻) | Ag⁺ + Cl⁻ → AgCl↓ (white) |
| | Brown Ring Test (for NO₃⁻) | FeSO₄ + H₂SO₄ | Brown ring at interface | NO₃⁻ + Fe²⁺ → [Fe(NO)]²⁺ (brown) |
| BaCl₂ Group | SO₄²⁻ | Barium Chloride Test | BaCl₂ + HCl | White ppt. | Ba²⁺ + SO₄²⁻ → BaSO₄↓ |
| Special Test Group | PO₄³⁻ | Ammonium Molybdate Test | (NH₄)₂MoO₄ + HNO₃ | Yellow ppt. | PO₄³⁻ + (NH₄)₂MoO₄ → (NH₄)₃[PMo₁₂O₄₀]↓ |