Solutions - a uniform system, which contain two or more components, as well as the products that are the result of the interaction of these components.They may be in solid, liquid or gaseous state.Consider the liquid state of aggregation solutions.The structure consists of a solvent and a substance dissolved in it (the latter less).
colligative properties - these are their characteristics that are directly dependent only on the concentration of the solution and the solvent.They also called collective or shared.Colligative properties are shown in the blends, in which there is no interaction between the chemical nature of their components.Moreover, the mutual action of forces between the particles and the particles of solvent-solvent and dissolved therein a substance are in ideal solutions.
colligative properties:
1) The vapor pressure above the solution lower than the above solvent.
2) Crystallization of the solution is at a temperature below the crystallization solvent in its pure form.
3) Boil the solution occurs at a higher temperature than the boiling of the solvent.
4) The phenomenon of osmosis.
Consider collegiate properties individually.
Balance at the phase boundary in a closed system: liquid - vapor is characterized by vapor pressure.Since in solution the surface layer portion is filled with solute molecules, the equilibrium will be achieved at lower vapor pressure.
second Collegiate property - lowering the temperature of crystallization of the solution compared with solvent - due to the fact that the particles of the solute to hinder the construction of the crystal and thus hinder the crystallization temperature decreases.
boiling point mixture is higher than the pure solvent due to the fact that the equality of atmospheric pressure and the vapor pressure is achieved at high heat because a part of the solvent molecules associated with the particles of the solute.
fourth colligative properties - the phenomenon of osmosis.
phenomenon of osmosis - the ability of the solvent to migrate through the barrier, which is permeable to certain particles (solvent molecules) and impermeable to other (molecules of dissolved substances).This partition separates the solution with a high content of solute from the less concentrated solution.An example of such a semipermeable membrane may serve as a membrane of a living cell, bovine and other bubble. Osmosis concentrations due to alignment on both sides separated by a membrane that is thermodynamically more favorable for the system.Due to displacement of the solvent in the more concentrated solution in this part of the vessel there is an increase in pressure.This overpressure was called osmotic.
colligative properties of non-electrolytes can be represented mathematically by the equations:
Δ bp. = Ekip ∙ See;
Δ Ta.= ∙ Kzam See;
π = CRT.
Colligative properties figure different for solutions of electrolytes and non-electrolytes solutions.For the former are somewhat larger.This is due to the fact that they occur in the electrolytic dissociation, and the amount of particles significantly increases.
colligative properties are widely used in the home and at work, for example, the phenomenon of osmosis is used to produce pure water.In living organisms, many systems are also built on colligative properties (for example, the growth of plant cells).
