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Practical Chemistry

Practical Chemistry for Class 12, JEE and NEET: Unit 20 lab work with no NCERT chapter, lyophilic and lyophobic sols and salt analysis of ions.

3 topics Updated 6 Nov 2026

For: JEE and NEET

In the syllabus: JEE Class 12 syllabus, NEET Class 12 syllabus

Learn in this order

  1. Experiment: preparation of lyophilic and lyophobic sols

    Egg albumin, starch and gum sols, and iron(III) and aluminium hydroxide sols, from NCERT.

    7 min read 2 solved examples 6 practice questions

  2. Experiment: salt analysis, anions

    Dilute and concentrated sulphuric acid groups, sulphate, and the confirmatory tests with equations.

    11 min read 2 solved examples 6 practice questions

  3. Experiment: salt analysis, cations

    Group reagents for groups zero to VI and confirmatory tests for each syllabus cation, with equations.

    13 min read 2 solved examples 6 practice questions

Key formulas in this chapter

Experiment: preparation of lyophilic and lyophobic sols

  • FeCl + 3HO → Fe(OH) (sol) + 3HCl
  • Colloid particle size: 10 to 10 m

Experiment: salt analysis, anions

  • FeSO + NO → [Fe(NO)]SO (brown ring)
  • 2Br + Cl → 2Cl + Br
  • Ba + SO → BaSO (white precipitate)

Experiment: salt analysis, cations

  • 4FeCl + 3K[Fe(CN)] → Fe[Fe(CN)] + 12KCl (Prussian blue)
  • Fe + SCN → Fe(SCN) (blood red)
  • Mg + HPO + NHOH → Mg(NH)PO + HO (with NaHPO)

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