CHEMCA - Cation Salt Analysis Virtual Laboratory

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Inorganic Salt Analysis Lab CATIONS

Qualitative Basic Radical Engine

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1. Lab Configuration

Study Mode

Target Basic Radical Ammonium (NH₄⁺) [Group 0] Lead (Pb²⁺) [Group I] Copper (Cu²⁺) [Group II] Iron (Fe³⁺) [Group III] Aluminium (Al³⁺) [Group III] Zinc (Zn²⁺) [Group IV] Nickel (Ni²⁺) [Group IV] Barium (Ba²⁺) [Group V] Calcium (Ca²⁺) [Group V] Magnesium (Mg²⁺) [Group VI]

❓ Cation is masked. Run diagnostic tests!

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2. Reagent Shelf

Systematic Group Reagents

Confirmatory Reagents

Auxiliary Tools

COLD GAS EVOLVING

Added Reagent NONE

Paper/Rod

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3. Live Lab Log

>> Initialized basic radical sample. Ready for testing.

Select reagents from the chemical shelf or execute flame tests.

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Observation Analyzer

Salt Initial Color: Colorless / White

Precipitate: No Precipitate

Evolved Gas: None

Flame Test: No characteristic flame

Litmus/Paper: N/A

Experimental Mechanism

Add systematic reagents to observe reactions. Complete diagnostic pathways with critical take-aways will reflect here.

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Balanced Equations

Trigger a reaction to view the balanced inorganic diagnostic equations.

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JEE/NEET Quiz

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📖 Analytical Chemistry: Group Classifications of Cations

Group 0 & Group I-II

Systematic group separation filters ions via cascading K_sp rules:

• ▹ Group 0 (NH₄⁺): Identified independently. Releases NH₃ gas with NaOH which turns Nessler's reagent brown.
• ▹ Group I (Pb²⁺): Reagent is dilute HCl. Precipitates as white PbCl₂.
• ▹ Group II (Cu²⁺): Reagent is dil HCl + H₂S. Precipitates as black sulfide (CuS) due to extremely low K_sp.

Group III & Group IV

Hydroxides and sulfides with moderately high solubility constants:

• ▹ Group III (Fe³⁺, Al³⁺): Reagent is NH₄Cl + NH₄OH. Precipitates as gelatinous hydroxides (Fe(OH)₃ - reddish brown, Al(OH)₃ - white).
• ▹ Group IV (Zn²⁺, Ni²⁺): Reagent is NH₄Cl + NH₄OH + H₂S. Zinc forms greyish-white ZnS; Nickel forms black NiS.

Group V & Group VI

Carbonates and phosphates analyzed near the final stages:

• ▹ Group V (Ba²⁺, Ca²⁺): Reagent is (NH₄)₂CO₃. Precipitate as white carbonates (BaCO₃, CaCO₃). Flame tests provide crucial signatures.
• ▹ Group VI (Mg²⁺): Confirmed with disodium hydrogen phosphate (Na₂HPO₄) forming white crystalline Mg(NH₄)PO₄.

👑 Group III Separation Logic:

NH₄Cl is added before NH₄OH during Group III analysis. The common ion effect of NH₄⁺ suppresses the dissociation of weak base NH₄OH, reducing [OH⁻] to a level that precipitates only Group III hydroxides with very low K_sp (like Fe(OH)₃ and Al(OH)₃). It prevents precipitation of higher group hydroxides like Mg(OH)₂.

🧪 Lake Test for Aluminium:

Confirms Al³⁺. Gelatinous Al(OH)₃ adsorbs blue litmus dye. Freshly precipitated Al(OH)₃ has an amphoteric surface that acts as an excellent adsorbent. It traps dye molecules, generating a floating blue solid mass ("lake") in a crystal-clear, colorless supernatant liquid.

🎯 Diagnosis

Based on your systematic group reactions and confirmatory tests, select the correct unknown basic radical:

Ammonium (NH₄⁺) [Group 0] Lead (Pb²⁺) [Group I] Copper (Cu²⁺) [Group II] Iron (Fe³⁺) [Group III] Aluminium (Al³⁺) [Group III] Zinc (Zn²⁺) [Group IV] Nickel (Ni²⁺) [Group IV] Barium (Ba²⁺) [Group V] Calcium (Ca²⁺) [Group V] Magnesium (Mg²⁺) [Group VI]

💡 Diagnostic Toast Message

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