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29 The manifestation of the chromatogram. Transfer the chromatogram for a while to a Petri dish with a solution of K 4 [Fe (CN) 6 ]. Observe the color of the fractions on the chromatogram. The chromatogram was dried. Describe the chromatogram obtained. Write the equation for the reactions that occur when the chromatogram was treated byK 4 [Fe (CN) 6 ]. Answer the questions: 1) how many colored zones are observed on the chromatogram? 2) how to explain the color of each zone? 3) which of the colored zones belongs to Cu  2+ ions and which of the Fe  3+ ions? 4) which ions, Cu  2+ or Fe  3+ , are better adsorbed on paper and why? 5) what types of chromatography on the technique of execution and the mechanism of the process refers to the work done? LESSON 13. COLLOIDAL SOLUTIONS AND THEIR PROPERTIES. THEORY OF COAGULATION Required base level. The idea of ​colloidal solutions. Selective adsorption, the Panet-Fayans rule. Dependence of the wavelength of light on color. Electrolytes, dissociation of acids, alkalis and salts. Questions for the preparation for the lesson. 1. Classification of disperse systems by the degree of dispersion; on the aggregate state of the phases. 2. Preparation, methods of preparation: dispersive and condensation methods. 3. Methods of purification: filtration, ultrafiltration, dialysis, electrodialysis. Physico-chemical principles of the functioning of an artificial kidney. 4. Optical properties: light scattering (Rayleigh law), Tyndall cone and opal- escence. 5. Electrokinetic properties: electrotrophoresis and electroosmosis. The structure of a double electrical layer. Electrothermodynamic and electrokinetic potentials and their dependence on various factors. Formulas of micelles, con- stituents of micelles. 6. Stability of disperse systems. Kinetic and aggregative stability of colloi- dal systems. Factors affecting the stability of lysozols. Coagulation. The coagu- lation threshold and its definition, the Schulze-Gardi rule. Colloidal protection. Input test-control on the topic «Disperse systems».