Group IV Cations Analysis Simulator

Group IV Cations Analysis

Precipitation of Co²⁺, Ni²⁺, Mn²⁺, Zn²⁺ using H₂S Gas in Alkaline Medium.

1. Setup Experiment

Select Unknown Filtrate

2. Observation

Physical State Clear Solution

Status: Standby.
Assume the filtrate from Group III. In Step 1, excess NH₄OH makes it alkaline, and Hydrogen Sulfide (H₂S) gas is passed through.

3. Chemical Principles

1. Precipitation: H₂S is passed in an alkaline medium (NH₄OH). The OH⁻ ions combine with H⁺ from H₂S to form water, driving H₂S ionization forward. This significantly increases S²⁻ concentration, allowing Group IV sulfides (which have higher Kₛₚ) to precipitate.

M²⁺ + S²⁻ → MS↓

2. Specific Tests:
• Ni forms a Cherry Red complex with DMG.
• Mn oxidizes to Purple HMnO₄ via NaBiO₃.
• Co forms Yellow Potassium Cobaltinitrite.
• Zn forms White Zinc Ferrocyanide.

Visual Key

Aqueous Solution

H₂S Gas Bubbles

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