📖 Theory & Concepts ▼

What is Dialysis?

Dialysis is the process of separating crystalloid (ionic) impurities from a colloidal solution using a semipermeable membrane (parchment/cellophane).

Principle:

Colloidal particles (1-1000 nm) cannot pass through the membrane, while smaller ions and molecules diffuse through.

Key Concepts

  • Electrodialysis: Using electric field to speed up removal of ionic impurities
  • Ultrafiltration: Using graded filters under pressure
Applications:

• Kidney dialysis (hemodialysis) - removes waste from blood

• Purification of colloids in industry

🎯 Objective

Purify a colloidal solution (Fe(OH)₃ sol) by removing ionic impurities using dialysis through a cellophane membrane.

Dialysis Setup

Distilled Water
Dialysis Bag
Cl⁻
Cl⁻
Fe³⁺
H⁺
Outer Vessel
Sol Purity:
30%

📚 Theory

Dialysis separates colloidal particles from crystalloids (ions) using a semipermeable membrane.

Membrane allows:
✓ Small ions (Cl⁻, H⁺, Fe³⁺) to pass through
Membrane blocks:
✗ Large colloidal particles (Fe(OH)₃)

Lab Notebook

Start dialysis to begin...