INTRODUCTION
Solutions with low freezing temperature based on water (antifreezes) are known in nature and are widely used in the technology of food production. The antifreeze composition comprises salts of inorganic and organic acids, alcohols, glycols, glycerin, acids and bases, amino acids and other compounds.
Formation of solutions is a spontaneous diffusion process proceeding from the thermal motion of constituent particles. Interaction force in the solution is evaluated by the osmotic pressure P, which depends on the concentration of the solute [1].
P = RT/V_1 ×ln(1-х) or after simplification P = RTc, where,
V1 – molar volume of the solvent, V1 = М/ρ;
М – molecular weight, ρ – density, х и с – mole fraction of the solute.
This equation describes the ideal, that is, rather diluted (thin) solutions (10-6 - 10-2 mole / dm3), in which osmotic pressure does not depend on the nature of the solvent and solute and is determined only by the number of interacting particles. Osmotic pressure is associated with the numerical average molecular weight of the solute:
М=RT m/П, where, m – molar concentration.
The osmotic properties of solutions include lowering the freezing point of the solvent (water) caused by the additive.
〖∆Т〗_(fr.)=К×m
K - cryoscopic constant of the solvent or the molar lowering of the solidification temperature of the solution. The indicator T characterizes the solvent and is independent of the nature of the solute (solid, liquid, gas). For water K = 1.86 ° C / mole.
For concentrated solutions, it is necessary to introduce osmotic correction factors that reflect the relationship of real and theoretical values. The composition of the resulting associates in the solution remains unknown, primary water clusters have not been established.
