Chemical and physical properties of water in liquid state, definitions and comments

All biochemical processes in humans are reduced to chemical reactions in aqueous solution. This is the metabolism in the body. In the liquid medium there is digestion of food and absorption into the blood of nutrients, with the help of water from the body, harmful exchange products are derived.

Water is the basis of our body. The cells of our body float in the intercellular fluid as a fish in the aquarium. The child in childhood is more saturated with water. Old age in biological sense is the loss of moisture by cells and exhaustion water resources Intercellular fluid. We "dried up", "scribble" and die. The greatest saturation of water in the tissues of the brain, liver, parenchymal organs. Even bones are 20% consisting of water. According to our arteries, veins, lymph nodes, liquid is also moving. We represent a system of reporting vessels, according to which the streams of various liquids interacting with each other are continuously moving.

For a second, the movement in the intercellular spaces does not stop. All this is due to the flow of nutrients into cells through the intercellular fluid and removing the used products through the same spaces. It is like rivers that sometimes turn into standing swamps - and then there are stagnation and illness, and when the rivers are accelerated - everything falls into place. We feel the state of these rivers through our well-being.

Water is an electrolyte. The parameters of our electrolyte are specific and are determined dissolved in water minerals, which serve as carriers of electrical charges.

An adult man uses an average of 2.5 liters of water per day. From this amount of 1.2 liters, it is necessary to drink water, 1l - on the water received from food, 0.3 liters of water is formed in the organism in the process of metabolism. The same amount of water is excreted from the body: 50% through the kidneys, 32% from then through the skin, 13% with exhaled air through the lungs, 5% via the intestine.

In nature, there are 48 varieties of water, each of them is inherent in its form of liquid crystals. When water freezing, under the influence of these crystals, all other water molecules turn into structured ice. It turns out that the structure of the protoplasm of the cell and the structure of the ice is organized like. After melting ice, the structure of crystals is preserved, so melt water is easily absorbed by the body. After water heating to 42, water loses its structure and turns into a normal.

Water inherent information memory. Each organism, including viruses and bacteria, has its own radiation frequency. All these radiation "are written" on water molecules. Poisoned water "remembers" about all poisonous processes, heavy metals, poisons with which they had contact. If this water gets into the body sooner or later cause a painful reaction.

Erase the previous information is very difficult, but recently it turned out that the freezing process erases this information, and after thawing the water, it becomes clean in the information sense.

Ordinary water is biologically not compatible with the internal environment. human organismTherefore, to use such drinking water in metabolic processes, the body spends the valuable energy of cell membranes to provide biocompatibility. This energy can be saved if used water with certain properties.

To optimize biochemical processes in the human body, water should have the following qualities:

Water should be biologically accessible, easily friendly. The degree of surface tension should not be too large. For water water This indicator is 73 din / cm while at intra and extracellular water 43 din / cm. The cell requires a large amount of energy to overcome this surface tension.

Water must be medium hardness. Very rigid water, as is very soft, are equally unsuitable for cells.

Water should be neutral, and better weakly alkaline. Most liquids in the body have a weakly alkaline reaction.

The redox potential of water should correspond to the same name of the intercellular liquid potential. In this case, the body will not need to spend energy on equalization of potentials.

Water must be structured. All water in the body is structured. Structured water is in intact fruits and vegetables.

Water should have as little as possible negative information. The transmission of such information the cell disrupts its biofrace and energy information characteristics.

Water should be weak-mineralized to maintain the electrolyte composition of the organism fluids.

Consider how the properties of water change when processing it.

Boiling water-destroys bacteria, coagulates colloidal particles of dirt, water is softened, volatile organic substances and part of the free chlorine evaporate. The concentration of salts of heavy metals, pesticides, organic substances increases. Chlorine associated with the organica, when heated, turns into a strong poison - carcinogen-dioxin, related to the category of particularly dangerous poisons. Dioxins are significantly more poisonous than potassium cyanide. In this way, boiled water Slowly kills us.

Water settling for 3 hours reduces the concentration of free chlorine, but does not remove iron ions, salts of heavy metals, carcinogenic chlorine-sanctuations, radionuclides and non-volatile organic matter.

Distillation of water deprives it the necessary organisms of trace elements. The constant use of such water leads to violations of the immune system, cardiac rhythm, digestive processes, and therefore distilled water is unsuitable for constant use.

Strictly speaking, in this material we will briefly consider not only chemical I. physical properties water in liquid state,but the properties inherent in it in general as such.

In more detail with the properties of water in solid state, you can find in the article -.

As noted above, in this material we will list the main physical and chemical properties of water and make short comments to some of them.

Physical properties of water

Physical properties are properties that manifest out of chemical reactions.

Purity of water

Purity of water - depends on the presence of impurities, bacteria, heavy metal salts ..., To familiarize themselves with the interpretation of the term, clean water according to our site, you need to read an article.

Water color

The color of water - depends on the chemical composition and mechanical impurities

For example, we give the definition of the "sea color", this "big Soviet encyclopedia".

Sea color. The color perceived by the eye when the observer looks at the sea surface, the sea color depends on the color of sea water, the color of the sky, the number and nature of the clouds, the height of the sun over the horizon and others. Reasons.

The concept of sea color should be distinguished from the concept of sea water. In the color of sea water, they understand the color perceived by the eye with a sheer inspection of seawater over a white background. From the surface of the sea, only a small part of the light rays falling on it is reflected, the remaining part of them penetrates deep into, where it is absorbed and dissipated by water molecules, particles of suspended substances and the smallest bubbles of gases. Reflected and emerging from the sea scattered rays and create C. m. Water molecules dispel the strongest blue and green rays. Weighted particles almost equally dispel all the rays. Therefore, sea water with a small amount of suspension seems to be a blue-green (the color of the open parts of the oceans), and with a significant amount of suspension - yellowish-green (for example, Baltic Sea). The theoretical side of the teachings on the C. m. Designed by V. V. Schuleikin and Ch. V. Raman.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978.

Water smell

The smell of water - clean water as a rule, does not smell.

Water transparency

The transparency of water depends on the mineral substances dissolved in it and the content of mechanical impurities, organic substances and colloids:

Water transparency - water ability to skip light. It is usually measured by the disk of the sect. It depends mainly on the concentration of organic and inorganic substances weighted and dissolved in water. It can dramatically decrease as a result of anthropogenic pollution and eutrophication of water bodies.

Ecological encyclopedic Dictionary. - Chisinau I.I. Sampi. 1989.

Water transparency - water ability to skip light rays. It depends on the thickness of the water layer passing by rays, the presence of suspended impurities, solutes, etc. in it. In water, the red and yellow rays are stronger, purple penetrate deeper. According to the degree of transparency, in order to reduce it, the water distinguish:

transparent;

weakly opalescent;

opalescent;

slightly muddy;

muddy;

very muddy.

Dictionary of hydrogeology and engineering geology. - M.: Gostoptekhizdat. 1961.

Taste of water

The taste of water - depends on the composition of solids dissolved in it.

Dictionary of hydrogeology and engineering geology

The taste of water is the property of water, depending on the salts and gases dissolved in it. There are tables with a tangible concentration of salts dissolved in water (in mg / l), for example, the following table (by staffu).

Water temperature

Water melting temperature:

The melting point is the temperature at which the substance passes from the solid state into the liquid. The melting point of the solid is equal to the freezing temperature of the liquid, for example, the melting point of ice, about ° C, is equal to the water freezing temperature.

Boiling water temperature : 99,974 ° C.

Scientific and Technical Encyclopedic Dictionary

The boiling point, the temperature at which the substance moves from one state (phase) to another, i.e. from the liquid to par or gas. The boiling point increases with increasing external pressure and decreases when it decreases. It is usually measured under standard pressure in 1 atmosphere (760 mm Hg. Art.) The boiling point of water under standard pressure is 100 ° C.

Scientific and technical encyclopedic dictionary.

Triple water point

Triple water point: 0.01 ° C, 611.73 Pa;

Scientific and Technical Encyclopedic Dictionary

Triple point, temperature and pressure at which all three states of the substance (solid, liquid, gaseous) can exist simultaneously. For water, the triple point is at a temperature of 273.16 K and a pressure of 610 RA.

Scientific and technical encyclopedic dictionary.

Surface water tension

Marigree

Water rigidity (Stiffness of Water) - the property of water, exstructable by the content of alkaline earth metals dissolved in it, ch. arr. Calcium and magnesium (in the form of biccarbonate bicarbonate salts), and salts of strong mineral acids - sulfur and salt. J. V. is measured in singular units, so called. degrees of rigidity. The degree of rigidity is called the weight content of calcium oxide (CAO), equal to 0.01 g in 1 liter of water. Rigid water is unsuitable for nutrition of boilers, as it contributes to the strong formation of scale on their walls, which can cause the loading of the boiler tubes. Boilers of high capacity and especially high pressures Must feed on perfectly purified water (condensate from steam machines and turbines, purified by filters from oil impurities, as well as distillates, prepared in special evaporator devices).

Samoilov K. I. Marigree. - M.-L.: State naval publishing house NKVMF Union of SSR, 1941

Scientific and Technical Encyclopedic Dictionary

Water rigidity, water inability to form foam with soap due to salts dissolved in it, mainly calcium and magnesium.

Cancer in boilers and pipes is formed due to the presence of a dissolved calcium carbonate in water, which falls into the water during contact with limestone. In hot or boiling water, calcium carbonate moves into a precipitate in the form of solid lime deposits On surfaces inside boilers. Calcium carbonate also does not give soaps to foam. The ion exchange container (3) is filled with granules covered with sodium-containing materials. With which the water comes into contact. Sodium ions as more active, calcium ions are replaced as sodium salts remain soluble even when boiling, it is not formed.

Scientific and technical encyclopedic dictionary.

Water structure

Under the structure of water means a certain arrangement of water molecules relative to each other. This concept is actively used in theory.

Water mineralization :

Ecological Encyclopedic Dictionary

Water mineralization - water saturation inorganic. (mineral) substances in it in the form of ions and colloids; The total amount of inorganic salts contained mainly in fresh water, the degree of mineralization is usually expressed in mg / l or g / l (sometimes in g / kg).

Ecological encyclopedic dictionary. - Chisinau: the main editorial office of the Moldavian Soviet Encyclopedia. I.I. Sampi. 1989.

The viscosity of water - characterizes the internal resistance of the particles of the liquid to its movement:

Geological Dictionary

Water viscosity (liquid) is a liquid property due to the occurrence of friction force when moving. It is a factor that transfers motion from water layers moving at high speed to layers at a lower rate. V. in. Depends on the temperature and concentration of the solution. Physically, it is estimated to coefficient. Viscosity, which is included in a series of water movement formulas.

Geological Dictionary: in 2 volumes. - M.: Nedra. Edited by K. N. Paffengolts and others. 1978

Distinguish two types of water viscosity:

Dynamic viscosity of water - 0.00101 Pa С (at 20 ° C).

The kinematic viscosity of water is 0.01012 cm 2 / s (at 20 ° C).

Critical point of water

The critical point of water is its condition with a certain ratio of pressure and temperature, when its properties are the same in a gaseous and liquid state (gaseous and liquid phase).

Critical point of water: 374 ° C, 22,064 MPA.

Dielectric permeability of water

The dielectric constant, in general, is a coefficient showing how much the power of the interaction between two charges in vacuum is more than in a certain environment.

In the case of water, this indicator is extremely high and for static electric fields equals 81.

Water heat capacity - water has surprisingly high heat capacity:

Ecological Dictionary

Heat capacity - the property of substances absorb heat. It is expressed in the amount of heat absorbed by the substance when it is heated at 1 ° C. The heat capacity of water is about 1 cal / g, or 4.2 j / g. The heat capacity of the soil (at 14.5-15.5 ° C) fluctuates (from sandy to peat soils) from 0.5 to 0.6 kal (or 2.1-2.5 J) per unit volume and from 0.2 up to 0.5 cal (or 0.8-2.1 J) per unit of mass (g).

Ecological dictionary. - Alma-Ata: "Science". B.A. Bulls. 1983.

Scientific and Technical Encyclopedic Dictionary

Specific heat capacity (designation C), heat needed in order to raise the temperature of 1 kg of substance to 1k. Measured in j / kg (where to j -jul). The substances with a high specific heat capacity, such as water, require more energy to raise the temperature than the substances with a low specific heat capacity.

Scientific and technical encyclopedic dictionary.

The thermal conductivity of the substance implies its ability to heat from its hotter parts to the colder.

Heat transmission in water occurs either at the molecular level, i.e. it is transmitted by water molecules, or due to the movement / movement of which or volume of water - turbulent thermal conductivity.

Pressability of water

The compressibility of water is insignificant.

Water electrical conductivity - largely depends on the amount of salts dissolved in them.

Water radioactivity

The radioactivity of water depends on the content of radon in it, radium emanation.

Physico-chemical properties of water

Dictionary of hydrogeology and engineering geology

Physico-chemical properties of water - parameters defining physico-chemical features natural Water. These include the indices of the concentration of hydrogen ions (pH) and the redox potential (EH).

Dictionary on hydrogeology and engineering geology. - M.: Gostoptekhizdat. Compiled by: A. A. Makkaveev, editor O. K. Lange. 1961.

Acid water equilibrium

Redox water potential

The redox water potential (ORP) is the ability of water to enter biochemical reactions.

Chemical properties of water

Chemical properties of a substance are properties that are manifested as a result of chemical reactions.

Below are given Chemical properties Water on the textbook "Basics of chemistry. Internet-tutorial "Authors A. V. Manuilova, V. I. Rodionova.

Metal Interaction

When water interacts with most metals, a reaction occurs with hydrogen release:

2NA + 2H2O \u003d H2 + 2NAOH (violently);
2K + 2H2O \u003d H2 + 2KOH (rapidly);
3Fe + 4H2O \u003d 4H2 + Fe3O4 (only when heated).

Not all, but only enough active metals can participate in oxidative and restorative reactions of this type. Alkaline and alkaline earth metals I and II groups are most easily reacting.

Interaction of water with non-metals

From non-metals with water react, for example, carbon and it hydrogen connection (methane). These substances are much less active than metals, but still capable of reacting with water at high temperatures:

C + H2O \u003d H2 + CO (with strong heating);
CH4 + 2H2O \u003d 4H2 + CO2 (with severe heating).

Electric Cleaning Water Interaction

When exposed to electric current, water decomposes into hydrogen and oxygen. It is also a redox reaction where water is both an oxidizing agent and a reducing agent.

The interaction of water with non-metal oxides

Water reacts with many non-metal oxides and some oxides of metals. This is not oxidative reaction reactions, but the connection reactions:

SO2 + H2O \u003d H2SO3 (sulfuric acid)

SO3 + H2O \u003d H2SO4 (sulfuric acid)

CO2 + H2O \u003d H2CO3 (coalic acid)

Metal oxide interaction

Some metal oxides can also enter into a reaction with water compound. Examples of such reactions we have already met:

Cao + H2O \u003d Ca (OH) 2 (calcium hydroxide (harated lime)

Not all metal oxides are able to react with water. Some of them are practically not soluble in water and therefore does not react with water. For example: Zno, TiO2, CR2O3, of which are prepared, for example, resistant paints. Iron oxides are also not soluble in water and do not react with it.

Hydrates and crystallohydrates

Water forms compounds, hydrates and crystallohydrates in which the water molecule is fully preserved.

For example:

CUSO4 + 5 H2O \u003d CUSO4.5H2O;
CusO4 - substance white color (anhydrous copper sulfate);
Cuso4.5H2O - crystallohydrate ( copper Kuner), Blue crystals.

Other examples of hydrate formation:

H2SO4 + H2O \u003d H2SO4.H2O (sulfur hydrate);
NaOH + H2O \u003d naoh.h2o (caustic satellite hydrate).

Compounds binding water into hydrates and crystallohydrates are used as dryers. With their help, for example, water vapors from wet atmospheric air are removed.

Biosynthesis

Water participates in bio-synthesis as a result of which oxygen is formed:

6N CO 2 + 5N H 2 O \u003d (C 6 H 10 O 5) N + 6N O 2 (under the action of light)

We see that the properties of water are diverse and covered almost all aspects of life on Earth. As one of the scientists formulated ... It is necessary to study the water comprehensively, and not in the context of its individual manifestations.

When preparing the material, information from books - Yu. P. Svadadkina "Water ordinary and extraordinary", Yu. Ya. Phialkov "Unusual properties of ordinary solutions", textbook "Basics of chemistry. Internet textbook "Authors A. V. Manuilova, V.I. Rodionova, etc.

Water has unusual properties. Its highest density is observed at a temperature of 4 ° C. When cooled fresh reservoirs in winter, as the temperature of the surface layers decreases, more dense weights of water are lowered down, and they rise in the bottom warm and less dense. This happens until water in the deep layers does not reach the temperature of 4 ° C. In this case, heat transfer is terminated, as heavier water will be at the bottom. Further cooling of water occurs only from the surface, which explains the formation of ice in the surface layer of reservoirs. Thanks to this, life does not stop under the ice.

Vertical stirring of sea water It is carried out by the action of wind, tides and changes in height density. Water mixing with wind occurs in the direction from top to bottom, tidal - bottom up. Dental mixing arises due to cooling surface water. Wind and tidal mixing spread to a depth of 50 m, only density mixing can affect high depths.

The intensity of the mixing of the bottom and surface waters contributes to their refreshment, enriching oxygen and nutrient substancesnecessary for life development. Air dissolved in water is always rich in oxygen than air atmospheric. Oxygen existing in water has beneficial influence The development of life processes in it.

When freezing, clean water expands, marine - to a smaller value. Since wateropri freezing expands, an increase in external decreases its freezing temperature; Tempe, melting melting, on the contrary, increases with pressure. In laboratory conditions at a pressure of more than 40 thousand. The atmospheres can be obtained by ice, which will melt at a temperature of 175 ° C. The heat capacity and heat pressure of ice decrease with the temperature, the thermal conductivity is almost independent of the temperature. The event of the ice on the surface of the water branch reaches 15 cm, it becomes a reliable coresolator between water and air. .

Sea water freezes at temperatures -1.91 ° \u200b\u200bC. With a further decrease in the temperature, the sedimentation of sodium sulfate, and only at a temperature of -23 ° C, sodium chloride falls out of the solution. Since part of the brine during crystallization goes from ice, salinity is less salinity of sea water. Many years of sea ice is so despicable that drinking water can be obtained from it. The temperature of the maximum seawater density is below the freezing temperature. This is the cause of a sufficiently fast transfer of heat that permeates a significant "waters of sea water and impellent freezing. The heat capacity of seawater is in third place after the heat capacity of hydrogen and liquid ammonia.

Sometimes water freezes and at the positive temperature. Such a phenomenon is observed in pipelines and soil capillaries. In pipelines, water can freeze at a temperature of + 20 ° C. This is explained by the presence of methane in water. Since methane molecules occupy about 2 times more than water molecules, they "sweat" water molecules increase the distance between them, which leads to a decrease in the internal pressure and increase the freezing temperature. In soil moisture, a similar role is performed by protein molecules. Due to the influence of protein molecules, the water freezing temperature in soil capillaries may increase to + 4.4 ° C.

The salinity of water depends on the concentration of salts dissolved in it, therefore, in different seas and oceans, the salinity of water is non-etinakov. The average salinity of the ocean water is 35%; The salinity of seawater can vary from zero near the deposit places of large rivers to 40% in the tropical seas. Water for drinking should contain less than 0.05% dissolved salts. For watering plants in water should be contained no more than 0.25% of salts, otherwise the plants will die.

The fluid existing in nature can be divided into normal and associated. Normal are the liquids in which molecules are not combined into groups (associations). Fluids that do not obey this condition are called associated. Water belongs to the number of associated liquids. If the water was non-associated, the melting point of ice under normal conditions would be + 1.43 ° C, and the boiling point of water is 103 ° C. As a rule, the heat capacity of liquids with temperature is growing, but the water with an approximation to the temperature + 35 ° C heat capacity after height decreases to a minimum, and then it gradually grows again. This is due to the fact that molecular ties are destroyed at such a temperature. The easier the molecular structure, the smaller the heat capacity of the substance. The temperature of the greatest water density is reduced with an increase in pressure and at a pressure of 150 atmospheres reaches 0.7 ° C. This is also explained by the change in the structure of molecular associations.

Among the fluids existing in nature, water has the greatest heat capacity. This quality has a significant impact on the climate. The main climate thermostat is the water of the oceans and the seas: accumulating heat in the summer, they give it in winter. The lack of water reservoirs usually leads to the formation of a sharp continental climate. Thanks to the influence of oceans, a significant part of the earth's steam is provided with precipitation on land over evaporation, and plant and animal organisms are obtained by them for life, the amount of water. Water I. air shell The globe is constantly exchanged carbon dioxide with rocks, plant and animal world, which also contributes to stabilization-PPI climate.

It is known that molecules that are on the surface of the liquid have an excess of potential energy and therefore tend to draw inside so that when: -the on the surface there remains a slight amount of molecules. Due to this, the strength is always valid along the surface of the liquid, seeking to reduce the surface. This phenomenon in physics got the name of the surface tension of the fluid.

Among the fluids existing in nature, the surface tension of water is inferior only to mercury. FROM surface tension Water is associated with its strong way (the ability to "stick" to the surface of many solids). In addition, water is a universal solvent. The heat of it is higher than the heat of the evaporation of any other liquids, and the heat of crystallization is only inferior to ammonia.

The water molecule consists of two hydrogen atoms and one oxygen atom. As part of the usual water of H2O, there is a small amount of heavy water D2O and a very small amount of superheavy waters t, about. In a molecule of heavy water, instead of ordinary hydrogen H - Datriol, its heavy isotope D is deuterium includes the composition of the superheavy water molecule there is an even more severe hydrogen isotope T - tritium. In natural water, 1000 molecules H, 0 accounts for two D2O molecules and one molecule T, 0 - 1019 H2O molecules.

Heavy water D2O is colorless, no smell, no taste and alive organisms are not absorbedi. Its temperature of its freezing is 3.8 ° C, the boiling point of 101.42 ° C and the temperature of the highest density is 11.6 ° C. By the ability to absorb heavy water close to sulfuric acid. Its density is 10% more than the density of natural water, and the viscosity exceeds the viscosity of natural water by 20%. The solubility of salts in heavy water is about 10% less than in ordinary water. Since the D2O evaporates slowly with light water, in the tropical seas and lakes more than in the reservoirs of polar latitudes.

Introduction

One of the most acute problems that stands today in front of humanity is a deficit of pure drinking water. The lack of water resources today already felt millions of people, especially acute this problem is in some countries of Asia and Africa. However, the latest developments of nanotechnology scientists can help humanity solve this problem and provide millions of people with clean drinking water.

A person consumes a huge amount of drinking water, and for drinking it is necessary to be clear, fresh and fresh drinking water. It is also necessary to take into account that more than 97% of the water on the globe is unsuitable for us. The remaining percentages of water resources are constantly polluted agriculture, industry and are lost in mind ineffective use. At the same time, the population of the planet is growing rapidly and according to experts, by 2030, 3.9 billion people (47% of the population) will not have access to clean drinking water. Some futurologists are already predicted by future wars that will be conducted by countries for sources of pure drinking water.

However, scientists at the moment can offer "tiny", but very effective solution This global problem. We are talking On nanotechnology. Nanomaterials are already being developed, which will be able to effectively purify polluted water from toxic compounds of metals or poisonous organic substances, and the most important thing will be able to convert salty seaside water in fresh.

So far, the productivity of such systems is low, but technology is very young and scientists promise her a big future. Already there is an interest in such materials from serious investors who are ready to invest in such research. According to experts, nanotechnologies will be able to play a major role in water purification already in the next 5 or 10 years.

However cleaning and disinfection fresh water - This is just one task that nanotechnology can solve. The second, probably even a more important task you need to decide, for the "thoughts" of the future world thirst - is the desalination of salt water. Really overwhelming part of water stocks on our planet is unsuitable for pythy. We are talking about the salted water of the seas and the oceans. Scientists who work in the field of nanotechnology and here are ready to "substitute shoulder" and offer a more efficient and less expensive method of desalination of salt water.

Basic requirements for drinking water

One of the main environmental problems Humanity is the quality of drinking water, which is directly related to the health of the population, the environmental purity of food, with the permission of medical and social problems. According to the World Health Organization (WHO) - 85% of all diseases in the world are transmitted to water. Every year, 25 million people die from these diseases. In new sanitary rules and the standards (San Pin 2.1.4.559-96) "Drinking water" identified indicators for viruses, tightened requirements for pesticides, and according to chlorine-containing substances the norms increased more than three times. This is due to the forced choice for cleaning the water of one of the two angry: to disinfect water with abundant chlorination and violate the norm on chlorine or compensate with the presence of bacteria in water. In chlorination of natural waters, chlorine-containing toxic, mutagenic and carcinogenic substances are formed - trigalometans. It should be noted that in the above mentioned Sanitary standards The lead and aluminum content is allowed, respectively, 3-10 times more than it is provided in WHO standards. It must be borne in mind that lead and aluminum belong to the class of high-wondrous substances.

Lead is postponed in the bones, leads to changes in the central nervous system (Polynevrites, cerebral arteriosclerosis), blood (reduced hemoglobin, decrease in the number of erythrocytes), gastrointestinal tract (spastic chronic colitis), as well as disruption of metabolism, "oppression" of many enzymes and hormones. Even a small amount of lead causes kidney defeat.

Aluminum paralyzes the nervous and immune systems, especially destroying it to the children's body, contributes to the development of Alzheimer's disease.

Long use of drinking water with impaired hygienic requirements By chemical composition, the development of various diseases in the population is determined. Adverse biological impact of redundant entry into the organism of a number chemical substances It is manifested not only in increasing the overall or specific incidence, but also in the change of individual health indicators, indicating the initial pathological or pre -tological shifts in the body.

Increasing the concentration of copper in drinking water causes the defeat of the mucous membranes of the kidney and the liver; Nickel - skin lesions; zinc - kidneys; arsenic - central nervous system.

Thus, drinking water is the most important human health factor. Almost all its sources are subjected to anthropogenic and technogenic effects of different intensity. Research suggests a deterioration in water quality since 1995 and that in a number of regions, the level of chemical and microbiological pollution of water bodies remains high, mainly due to the discharge of untreated industrial and domestic wastewater. Despite relative security underground water From contamination, therefore they are striving to use for drinking water supply, it has now been detected about 1800 foci of their pollution, 78% of which are in the European part of the Russian Federation. Due to the lack of facilities for cleaning and disinfection of water on most water pipes with water intake from open water bodies, the state of the sources of centralized water supply as a whole in the country is extremely unfavorable.

Physiochemical properties water

In the nineteenth century was open chemical formula this compound H 2 O, which, as it seemed, gives full information About the water, but in 1932 a new sensational fact was opened - in addition to ordinary water, there is also the concept of "hard" water, and today up to 135 isotopic varieties of water are already known. The composition of the separate water drops, subject to its complete purification of the impurities of mineral and organic substances, is always unique, and its properties change depending on physical nature The components of its atoms, the method of forming a molecule, and from the combination of these molecules in the chemical compound.

One of the most wonderful and at the same time impede water study by the property, is the ability of water to act as universal solvent. Any substance, whether it is in a solid, liquid or gaseous state, necessarily soluble in water to some extent, so water is always a solution having a very complex chemical composition. And even when the chemical composition of water taken in various places is completely identical, it turns out that water has a completely different effect on the body, since water formation conditions also determine its properties.

It should be noted that in nature there is no absolutely clean water, and the closest to this concept is rainwaterAlthough even it in its composition has some impurities that fall into it from the air. And the most characteristic solvent is marine water, as it can dissolve almost any substance, and its composition may include up to 70 elements periodic system Mendeleev, starting with chlorine, magnesium, sodium, sulfur, calcium and potassium, bromine, carbon, strontium and boron, which are contained in seawater in large quantities, and ending with the rarest radioactive elements in very small pieces.

Depending on the content of various impurities in the water, it can be divided into several classes: fresh water, salt and brine. The color of water depends on it. At first glance, any water is a transparent colorless liquid that does not have any taste, no smell, however deep waters the sea or ocean look blue, and the water of mountain rivers seems green, it is the presence of various impurities in the water gives her different color. It would seem, with modern equipment and technologies today, we know everything about water, but new and new facts are opening up, which show that water has an undisclosed potential, which is still to learn humanity.

It turns out that water not only from ancient times is used to meet the household and industrial needs of a person, but also protects the land in the summer of overheating, and in winter, giving her his warmth, from moving. Excess carbon dioxide, produced in the process of human life, could lead to disastrous consequences, if it were not absorbed by the waters of the World Ocean.

Water has specific properties that are not inherent in a non-one chemical compound, so, for example, when moving water from a liquid state into solid, it does not increase its density, but increases the volume. This is due to the molecular structure of the ice: during freezing the molecule is located at a considerable distance from each other, forming a loose structure of ice, thereby increasing the volume, but maintaining the mass, thus, the water in the solid state (ice), is lighter than in liquid. Do not possess water by this property, the emergence of life on Earth would not have possible, since the ice that arose on the surface of the water was immediately silent and rivers, the sea and even the oceans would freeze until the bottom. So, one of the factors determining the properties of water is its molecular composition. The water molecule is an equifiable triangle at the base of which the hydrogen atoms lie, and the vertex is an oxygen atom, the valence angle of this triangle is 104.31 °, and the hydrogen atoms are so closely adjacent to the oxygen atom, which at first glance, the molecule has a spherical shape. . Water molecule has weak hydrogen bonds, which allows water to evaporate, that is, if placing water in open Vessel, then gradually all water molecules will go into the air. If the vessel is closed, then the water will evaporate until some equilibrium is achieved, which is explained by the pressure exerted by the water vapor molecules, which accumulated between the vessel lid and the remaining water. Evaporation occurs even in a solid state of water, that is, from the surface of ice or snow. In this case, the viscosity of the water directly depends on its temperature, the higher the temperature, the less viscosity, when the water boiling point is reached, the viscosity decreases 8 times than at its freezing point. Water is almost impossible to compress, and its density is maximum at 4 ° C.

physical characteristics The water is such that it moves from a solid into a liquid state and vice versa (melts and freezes) at the same temperature of 0 ° C. The boiling point of water is 100 ° C, although here water shows interesting properties: this rule is observed only when normal pressurewhich is 760 mm Hg. Art., With a decrease in pressure, the boiling point of water is reduced, so at an altitude of 2900 m above sea level, where the atmospheric pressure is 525 mm Hg. Art., the boiling point of water is 90 ° C.

The land is 75% covered with water, and the nature is constantly maintained by the natural cycle of water: it evaporates from the surface of the reservoirs, and then falls in the form of precipitation: rain or snow, but even with such a reasonable solution, some areas of the globe are constantly suffering from lack of fresh water. That is why it is worth remembering that the water is the greatest wealth given to us by nature, and each of her drop is precious, because human life is impossible without water.

Three water states

Water is one of the most common chemical compounds on Earth. She surrounds us everywhere, even natural phenomena, every day observed by us - cloudiness, fog, rain, snow - just different water states, gaseous and solid. After all, the cloud is nothing but a cluster of many smallest droplets of water or ice crystals, which fall out in the form of precipitation - rain (liquid water condition) or snow (solid condition of water). If you look at the snowflake under a microscope, then it can be noted that this beautiful natural work of art is created from very small ice crystals. Gaseous condition of water is customary to call the ferry. In nature, the concept of humidity of air implies the content of the amount of water vapor in the air (large content of vapors - increased humidity air). At 0 ° C and lower and normal atmospheric pressure Water goes into a solid state - ice. The ice is very poorly compressing, and the density of ice, due to its molecular structure, less water density, so the ice is on the surface of the water and at a temperature of 0 ° C always performs from it on 1/5 of its volume.

WATER

The water molecule consists of an oxygen atom and two hydrogen atoms connected to it at an angle of 104.5 °.

The angle of 104.5 ° between the bonds in the water molecule determines the looseness of ice and liquid water and, as a result, an abnormal dependence of the temperature density. That is why large water bodies are not freezing to the bottom, which makes it possible to exist in them life.

Physical properties

Water, ice and par,accordingly, liquid, solid and gaseous state chemical compound Molecular formula H 2 O.

Due to the strong attraction between water molecules, high melting temperatures (0c) and boiling (100 ° C). The thick layer of water has a blue color, which is determined not only by its physical properties, but also the presence of suspended particles of impurities. The water of mountain rivers is greenish due to the weighted particles of calcium carbonate contained in it. Clean water is a bad electricity conductor. The water density is maximal at 4C it is 1 g / cm 3. Loda has a smaller density than liquid water and pops up onto its surface, which is very important for inhabitants of water bodies in winter.

Water has an exceptionally large heat capacity, so it slowly heats up and slowly cools. Thanks to this, water pools adjust the temperature on our planet.

Chemical properties of water

Water is a very reactive substance. For conventional conditions It interacts with many major and acid oxide, as well as with alkaline and alkaline earth metals. Water forms numerous compounds - crystallohydrates.

Under the influence electric current Water decomposes on hydrogen and oxygen:

2 H 2 O electricity \u003d 2 H 2 + O 2

Video "Electrolysis of Water"