Title: Step-by-Step Qualitative Analysis of Barium Chloride (BaCl₂)
Introduction
Barium chloride (BaCl₂) is a water-soluble ionic compound commonly used in laboratory testing and chemical analysis. This document outlines the qualitative analysis of BaCl₂ to identify its cation (Ba²⁺) and anion (Cl⁻) through systematic tests.
Step-by-Step Analysis of BaCl₂
1. Preliminary Examination
| Property | Observation |
|---|---|
| Physical Appearance | White crystalline solid |
| Solubility | Soluble in water, forming a colorless solution |
| Odor | Odorless |
2. Dry Heating Test
| Procedure | Observation | Inference | Chemical Equation |
| Heat a small sample in a dry test tube. | No decomposition or characteristic odor observed. | Indicates stability of BaCl₂ at moderate temperatures. | No reaction |
3. Flame Test
| Procedure | Observation | Inference |
| A platinum wire is dipped in BaCl₂ solution and introduced to a non-luminous flame. | Greenish-yellow flame is observed. | Confirms the presence of Ba²⁺ ions. |
4. Identification of Barium (Ba²⁺) Ion
| Test | Reagent Used | Observation | Inference | Chemical Equation |
| Sulfuric Acid (H₂SO₄) test | Dilute H₂SO₄ solution | White precipitate | Confirms Ba²⁺ presence | Ba²⁺ + SO₄²⁻ → BaSO₄ (white ppt.) |
| Ammonium Carbonate ((NH₄)₂CO₃) test | (NH₄)₂CO₃ solution | White precipitate | Confirms Ba²⁺ presence | Ba²⁺ + CO₃²⁻ → BaCO₃ (white ppt.) |
5. Identification of Chloride (Cl⁻) Ion
| Test | Reagent Used | Observation | Inference | Chemical Equation |
| Silver Nitrate (AgNO₃) test | AgNO₃ solution | White precipitate, soluble in NH₄OH | Confirms Cl⁻ presence | Cl⁻ + Ag⁺ → AgCl (white ppt.) |
| Conc. Sulfuric Acid (H₂SO₄) test | Conc. H₂SO₄ + heat | Dense white fumes of HCl gas | Confirms Cl⁻ presence | BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl (gas) |
6. Group Analysis of Ba²⁺ (Cation Analysis)
Barium ion (Ba²⁺) belongs to Group V in cation analysis, which includes Ba²⁺, Sr²⁺, and Ca²⁺. The group reagent used for its identification is ammonium carbonate ((NH₄)₂CO₃) in the presence of ammonium chloride (NH₄Cl) and ammonia (NH₄OH).
| Test | Reagent Used | Observation | Inference | Chemical Equation |
| Group Precipitation | (NH₄)₂CO₃ in presence of NH₄Cl and NH₄OH | White precipitate | Confirms Ba²⁺ presence | Ba²⁺ + CO₃²⁻ → BaCO₃ (white ppt.) |
| Flame Test | Platinum wire in non-luminous flame | Greenish-yellow flame | Confirms Ba²⁺ | Ba²⁺ produces a characteristic flame color |
Conclusion
The qualitative analysis of BaCl₂ confirms the presence of barium (Ba²⁺) and chloride (Cl⁻) ions through distinct chemical reactions, solubility tests, and confirmatory tests.