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26 The method of determination is based on the reaction of oxidation of H2O2 with potassium permanganate in the presence of H 2 SO 4 . Make up the equation of the reaction, arrange the coefficients by the electronic balance method. Way of work: transfer 10 ml of a control solution of hydrogen peroxidein three flasks for titration, add 3 ml of sulfuric acid to each. Then titrate from the burette with a solution of potassium permanganate to a slightly pink color. Calculate the average volume of the potassium permanganate solution. The mo- lar concentration of the hydrogen peroxide equivalent in the control solution is calculated by the formula: 4 4 2 2 2 2 (KMnO ) (KMnO ) (H O ) (H O ) eq a eq С V С V ⋅ = LESSON 12. SURFACE PHENOMENON. ADSORPTION Required base level. The second law of thermodynamics. The structure of organic acids, alcohols, amines. The concept of polar and nonpolar solvents. Amodel of the structure of biological membranes Questions for the preparation for the lesson. 1. Coefficient of surface tension; factors affecting it. Surface-active, surface- nonactive and surface-inactive substances. Surface activity. Rule Duclos- Traube. Isotherms of surface tension. 2. Adsorption on the mobile interface. Gibbs ‘ Equation. 3. The theory of the Langmuir monomolecular layer. Langmuir adsorption equation and its analysis for different values of equilibrium concentrations. Orientation of surfactant molecules in the surface layer. Amodel of the structure of biological membranes. 4. The Freundlich Equation. A graphical way of defining constants in the Freundlich equation. 5. Adsorption on the stationary interface, the factors affecting it. The equation of molecular adsorption. 6. Ion adsorption. Selective adsorption. Panet-Faience Rule. 7. Ion-exchange adsorption. 8. Methods of adsorption therapy.