It is necessary to consider an ability of water to dissolve various substances, as a remarkable and important property, it is the strongest natural solvent: almost all substances are dissolved in water to the certain degree. The significant removal of the positive charges centers from negative in a molecule of water leads to that the molecules are guided in an electrical field, intending to neutralize it. In the other words, they have a high dipole moment, that provides uniquely high meaning of dielectric constant of water, the highest among all liquids. As a result, any charges in water are drawn with force, 80 times greater, than in vacuum. It provides high solubility of substances in water, as the molecules of water "take away" particles or ions of substances, the force of an attraction between which is weakened. This also provides "sticking" and high ability of wetting. The surfaces of things, put in water, become less strong. The substance begins to be dissolved in water, breaking up on separate molecules, as sugar in a glass of tea, or on the charged ions, as the cooking salt.
Hundreds, or probably thousand, of various combinations of all elements of the Mindeleev table are always dissolved in water. The dissolved substances also influence the structure of water, and consequently - its properties. The process of dissolution itself is rather frequently accompanied by allocation of heat. The better the substance is dissolved, the more heat is allocated. However there are some unexpectedness with water.
There are interesting processes at dissolution. If we dissolve the usual cooking salt in a distilled water to so to get 1 kg of sea water, the downturn of temperature of water will coinside the loss of energy of approximately 2514 kJ. Besides, the volume of a solution will be less, than the sum of initial volumes of water and salt. The solution will be as though compressed. This phenomenon is called electrostriction. Each ion in a solution is enveloped with molecules of water. The condensation reaches several tenths of percent from volume. Therefore, when two natural weights of water with different temperature, but identical density, mix up there is a condensation of the mixed solution. This phenomenon has essential meaning for dynamics of hydrosphere.
The substances, dissolved in water, changing its structure, also change its properties. So, when plenty of ions, carrying electrical charges, appear in water, electroconductivity of solutions usually grows in thousands of times. Temperature of freezing of water falls. For example, sea water freezes at temperature -1,9 °C, but the ice, which is formed of sea water is sweet, though the originally arising ice comprises pockets with salty water. The old sea ice is usual fresh. In the last century it has even caused a determination, that sea water does not freeze. The ice cover of Arctic ocean was considered to be a congestion of the river ice, born by the rivers. M.V. Lomonosov accepted this point of view. In that time Antarctic continent was not discovered yet and seafarers, observing huge icebergs, considered about the great rivers of southpole continent bearing such huge pieces of ice. Now this property of selffreezing of salts from strongly mineralized water is used in droughty and, at the same time, cold areas for getting of fresh water from salty underground waters.
Temperature of freezing of water is lowered at increase of pressure, that corresponds to dissolution of salts in it. Increasing the pressure up to the very large volumes, the ice, formed in such conditions, becomes heavy drowns in water. At the further increase of pressure it again becomes easier than water, but its melting temperature raises up to 80°C. There are also such modifications of ice of high pressure, which melt at 175°C ,so the ice can become hot.
Water is necessary for alive creatures, as is the inert solvent, which usually does not get in reaction with the dissolved substance. This property is extremely important, because the water serves the inert carrier of various vital substances in alive systems.
