Section I.
DESIGN OF WELLS FOR WATER
Chapter 1. SOME INFORMATION ABOUT WATER

Water anomalies

The composition of ice is dominated by trihydrol molecules, in the composition of water vapor (at temperatures above 100°C) - hydrol molecules, and in droplet-liquid water - a mixture of hydrol, dihydrol and trihydrol, the ratios between which change with temperature.

The following anomalies are determined by the peculiarities of the water structure:

1) water has the greatest density at 4 °C, with a decrease in temperature to 0 °C or an increase to 100 °C, its density decreases;

2) the volume of water during freezing increases by approximately 10%, while the solid phase becomes lighter than the liquid;

3) water has a high specific heat capacity, which decreases with increasing temperature to 40 °C and then increases again;

4) water has a very high specific internal energy (318.8 J/kg);

5) water freezes at 0 °C, with increasing pressure the freezing point decreases and reaches its minimum value (-22 °C) at a pressure of 211.5 MPa;

6) water has the largest specific amount of heat (2156 J/kg) at a temperature of 100 °C;

7) water has the highest dielectric constant at 20 °C;

8) water has the highest surface tension compared to other liquids.

When interacting with alkalis, water behaves like an acid, and when interacting with acids, it behaves like a base. During the reaction of active metals and water, hydrogen is released. Water causes a process of exchange decomposition (hydrolysis) by interacting with certain salts.

7. Water anomalies

Chemically pure water has a number of properties that sharply distinguish it from other natural bodies and chemical analogs (hydrides of elements of group 6 of the Mendeleev periodic system) and from other liquids. These special properties are known as water anomalies.

Studying water and, especially its aqueous solutions, scientists were convinced over and over again that water has abnormal - anomalous properties inherent only to it, Her Majesty - Water, which gave us Life and the ability to think. We don’t even suspect that such familiar and natural properties of water in nature, in various technologies, and finally in our everyday life are unique and inimitable.

Density

For the entire biosphere, an extremely important feature of water is its ability to increase rather than decrease its volume when frozen, i.e. reduce density. Indeed, when any liquid transforms into a solid state, the molecules are located closer together, and the substance itself, decreasing in volume, becomes denser. Yes, for any of the vastly different liquids, but not water. Water is an exception here. When cooling, water initially behaves like other liquids: gradually becoming denser, it reduces its volume. This phenomenon can be observed up to +3.98°C. Then, with a further decrease in temperature to 0°C, all the water freezes and expands in volume. As a result, the specific gravity of ice becomes less than water and the ice floats. If the ice did not float, but sank, then all bodies of water (rivers, lakes, seas) would freeze to the bottom, evaporation would sharply decrease, and all freshwater animals and plants would die. Life on Earth would become impossible. Water is the only liquid on Earth whose ice does not sink due to the fact that its volume is 1/11 greater than the volume of water.

Surface tension

Due to the fact that round balls of water are very elastic, it rains and dew falls. What is this amazing force that preserves dew drops and makes the surface layer of water in any puddle elastic and relatively durable?

It is known that if a steel needle is carefully placed on the surface of water poured into a saucer, the needle does not sink. But the specific gravity of the metal is much greater than that of water. Water molecules are bound by the force of surface tension, which allows them to rise up the capillaries, overcoming the force of gravity. Without this property of water, life on Earth would also be impossible.

Heat capacity

No substance in the world absorbs or releases as much heat to the environment as water. The heat capacity of water is 10 times greater than the heat capacity of steel and 30 times greater than mercury. Water retains heat on Earth.

From the surface of the seas, oceans, and land, 520,000 cubic kilometers of water evaporate per year, which, when condensed, give off a lot of heat to the cold and polar regions.

Water in the human body makes up 70-90%. from body weight. If water did not have such a heat capacity as it does now, metabolism in warm- and cold-blooded organisms would be impossible.

Water heats up most easily and cools down most quickly in a kind of “temperature pit” corresponding to +37°C, the temperature human body.

There are several more anomalous properties of water:

No liquid absorbs gases as greedily as water. But she also gives them away easily. Rain dissolves all the poisonous gases of the atmosphere. Water is its powerful natural filter, purifying the atmosphere from all harmful and poisonous gases. Another amazing property of water appears when it is exposed to a magnetic field. Water subjected to magnetic treatment changes the solubility of salts and the rate of chemical reactions.

But the most amazing property of water is the property of an almost universal solvent. And if some substances do not dissolve in it, then this also played a huge role in evolution for life: most likely, life owes its appearance and development in the aquatic environment to the hydrophobic properties of primary biological membranes.

Water known and unknown. Memory of water

Bromine water is a saturated solution of Br2 in water (3.5% by weight Br2). Bromine water is an oxidizing agent, a brominating agent in analytical chemistry. Ammonia water is formed when raw coke oven gas comes into contact with water...

Water as a reagent and as a medium for a chemical process (anomalous properties of water)

The role of water in modern science and technology is very great. Here are just some of the areas where water can be used. 1. In agriculture for watering plants and feeding animals 2. In the chemical industry for producing acids, bases, organic substances. 3...

Water that gives life

Water is the most important chemical compound that determines the possibility of life on Earth. A person's daily consumption of drinking water averages about 2 liters...

Hydrogen - the fuel of the future

The next problem where weightlessness reasserted itself was the problem of draining the water formed in the fuel cell. If it is not removed, it will cover the electrode with a film and make it difficult for gas to access it...

Information-structural memory of water

A water molecule is a small dipole containing positive and negative charges at its poles. Since the mass and charge of the oxygen nucleus is greater than that of the hydrogen nuclei, the electron cloud is pulled towards the oxygen nucleus...

Determination of water hardness using the complexometric method

Due to the widespread occurrence of calcium, its salts are almost always found in natural water. Of the natural calcium salts, only gypsum is somewhat soluble in water, however, if the water contains carbon dioxide...

Calculation and selection of an evaporation plant

Gv is determined from the thermal balance of the condenser: Gv=W3(hbk-svtk)/cv(tk-tn), where hbk is the enthalpy of vapor in the barometric condenser; tн = 200С - initial temperature of cooling water; Cv =4...

Calculation and design of a double-effect evaporation plant

The cooling water flow rate GВ is determined from the thermal balance of the condenser: , where IБК is the enthalpy of vapor in the barometric condenser, J? kg; tн - initial temperature of cooling water, 0С...

Sorptive water purification

In production it is installed depending on the requirements of the technological process. Water used in production...

Sorptive water purification

To prevent the development of bacterial biological fouling in heat exchangers, as well as in pipelines, it is recommended to periodically use chlorination of water 3-4 times a day, each period lasting 40-60 minutes...

Sorptive water purification

One of the most common types of water conditioning is its softening. The first industrial method for removing hardness salts was soda-lime...

Calcium sulfate, crystal hydrate and anhydrous salt

Amazing substance - water

Hydrology is a science that studies natural waters, their interaction with the atmosphere and lithosphere, as well as the phenomena and processes that occur in them (evaporation, freezing, etc.). The subject of the study of hydrology is all types of hydrosphere waters in the oceans...

Water. Anomalous properties of water and their causes

Since water is a universal solvent, let's consider the properties of water. The most common substance on earth is water. Almost 3/4 of the surface of the globe is covered with water. It is the medium in which chemical processes occur in living organisms and itself takes part in biochemical processes.

Water is the main catalyst of all life processes. Our body is 65-75% water. A person’s daily need for water ranges from 2 to 6 liters and dependence on it is much stronger than on food. Many foods (vegetables, fruits, milk, meat) consist of 95-65% water. Humanity widely uses natural water for its needs. The bulk of the water comes from the World Ocean. The reserves of fresh water available for use account for 0.15% of the volume of the hydrosphere.

Physical properties. It is a colorless and odorless liquid. Let us consider the features of physicochemical properties ( anomalies) water.

1. Water has an abnormally high polarity as a solvent.

µ = 1.84·10 -29 Cm (for H 2 S - µ = 0.93·10 -29 Cm).

2. Water has an anomalously high heat capacity c = 75.3 J/mol K, alcohol has 1.5 times more, therefore at night and during the transition from summer to winter it cools down slowly, and during the reverse transition it heats up slowly, t .O. regulating the temperature of the globe. When heating any substance except water from 0 to 37 o C, the heat capacity increases, and that of water decreases, then increases. It is at 37 o C that the body expends less energy to maintain body temperature.

3. Abnormally high temperature Tmelt = 0 o C and temperature Tbp = 100 o C compared to analogues.

4. At 0 o C water freezes. The density of ice is less than that of water. At the same time, the volume of ice increases by 9%. For other substances it decreases.

5. The density of water during the transition from solid to liquid does not decrease, but increases. When water is heated from 0 to 4 o C, its density also increases. The density of water reaches its maximum value at 4 o C - ρ = 0.998 g/cm 3 .

The anomalies are associated with the structure of the water molecule and the formation of a hydrogen bond between them.

The water molecule has an angular structure. The oxygen atom in a water molecule is in a state of sp 3 hybridization. For this reason, the bond angle is close to tetrahedral (109 o 28").

The formation of a hydrogen bond leads to the association of molecules. Each oxygen atom takes part in the formation of two hydrogen bonds. During crystallization, molecules form layers, each connected to three molecules in this layer and to one of the neighboring ones. This leads to the formation of voids.

When ice melts, only part of the hydrogen bonds are destroyed and the volume of water decreases. At 0 o C, water contains remnants of the ice structure. From 0 to 4 o C, the density of water increases due to the destruction of ice.

The high heat capacity of water is explained by the heat consumed to break hydrogen bonds.

Chemical properties. The H 2 O molecule is resistant to heat. At temperatures above 1000 o C it undergoes thermal dissociation, ᴛ.ᴇ. decomposition

H 2 O ↔ 2 H 2 + O 2

This process occurs with the absorption of heat.

Water is a very reactive substance. Oxides of many metals and non-metals combine with H 2 O to form:

CaO + H 2 O = Ca(OH) 2

SO 3 + H 2 O = H 2 SO 4

Active metals react with water to release H2.

Water forms compounds with substances that are not chemically active (xenon hydrate - Xe 6 H 2 O). Xe fills the intermolecular space in the H 2 O structure, forming compounds called clathrates .

“Water is life” - we have known this saying since childhood, but we do not always attach importance to what constantly surrounds us, which we cannot do without.

Do you know what “WATER” is?

“Water, you have no taste, no color, no smell, you cannot be described, they enjoy you without knowing what you are.”

Antoine de Saint-Exupery.

First, I will give some examples from history so that you understand that this question is not so simple!

According to the chronicles, in 1472, Abbot Charles Hastings was captured and interrogated on the basis of a false denunciation for inducing illness on a certain respected woman. The imprisoned abbot was given only a piece of dry bread and a ladle of rotten, stinking water every day. After 40 days, the jailer noticed that during this time the Monk Charles not only did not lose, but seemed to have gained health and strength, which only convinced the inquisitors of the abbot’s connection with evil spirits. Later, under severe torture, Karl Hastings admitted that over the rotten water that was brought to him, he read a prayer, thanking the Lord for the trials sent down to him. After which the water became soft in taste, fresh and clear.

In history, there are known cases of changing the structure of water through the influence of thought. For example, in the winter of 1881, the ship Lara was on a flight from Liverpool to San Francisco. On the third day of the voyage, a fire started on the ship. Among those who left the ship was Captain Neil Carey. Those in distress began to experience the pangs of thirst, which increased with each passing hour. Then, when, after a painful wandering across the sea, they safely reached the shore, the captain, a man with a very sober attitude to reality, described in the following words what saved them: “We dreamed of fresh water. We began to imagine how the water around the boat turned from blue sea to greenish fresh. I gathered my strength and scooped it up. When I tried it, it was bland."

Briefly about water from a biochemical point of view

Water is the most abundant substance on Earth. Its quantity reaches 1018 tons, and it covers approximately four-fifths of the earth's surface. Water occupies 70% of the Earth's surface. The same amount (70%) is in the human body. The embryo consists almost entirely (95%) of water, while in the body of a newborn it is 75%. Only in old age the amount of water in the human body is 60%. This is the only chemical compound that under natural conditions exists in the form of liquid, solid (ice) and gas (water vapor). Water plays a vital role in industry and everyday life; it is absolutely necessary to maintain life. Of the 1018 tons of water on Earth, only 3% is fresh water, of which 80% is unusable because it is ice that forms the polar caps. Fresh water is available to humans as a result of participation in the hydrological cycle, or the water cycle in nature. Every year, approximately 500,000 km 3 of water is involved in the water cycle as a result of its evaporation and precipitation in the form of rain or snow. Theoretically, the maximum amount of fresh water available for use is approximately 40,000 km 3 per year. We are talking about the water that flows from the surface of the earth into the seas and oceans.

The properties of water are unique. A transparent liquid, odorless, tasteless and colorless (molecular weight – 18.0160, density – 1 g/cm3; a unique solvent, capable of oxidizing almost all metals and destroying hard rocks). Attempts to imagine water as an associated liquid with a dense packing of water molecules, like balls of any container, did not correspond to elementary factual data. In this case, the specific density of water should not be 1 g/cm3, but more than 1.8 g/cm3.

Spherical water drops have the smallest (optimal) volume surface. Surface tension is 72.75 dynes/cm. The specific heat capacity of water is higher than that of most substances. Water absorbs a large amount of heat, while heating up little.

The second important evidence in favor of the special structure of the water molecule was that, unlike other liquids, water - this was already known - has a strong electrical moment, which makes up its dipole structure. Therefore, it was impossible to imagine the presence of a very strong electrical moment of a water molecule in a symmetrical structure of two hydrogen atoms relative to an oxygen atom, placing all the atoms included in it in a straight line, i.e. N-O-N.

The structure of water in a living organism is in many ways similar to the structure of the crystal lattice of ice. And this is precisely what now explains the unique properties of melt water, which preserves the structure of ice for a long time. Melt water reacts with various substances much more easily than ordinary water, and the body does not need to spend additional energy on restructuring its structure.

In liquid form, the bonds of neighboring water molecules form unstable and fleeting structures. When frozen, each ice molecule is tightly bound to four others.

Doctor of Biological Sciences S.V. Zenin discovered stable long-lived water clusters. It turned out that water is a hierarchy of regular volumetric structures. They are based on crystal-like formations consisting of 57 molecules. And this leads to the appearance of higher order structures in the form of hexahedrons consisting of 912 water molecules. The properties of clusters depend on the ratio of oxygen and hydrogen protruding to the surface. The configuration reacts to any external influence and impurities. Coulomb attractive forces act between the faces of cluster elements. This allows us to consider the structured state of water in the form of a special information matrix.

The Unsolved Properties of Water

Water has always been a great mystery to the human mind. Much remains incomprehensible to our minds in the properties and actions of water. By watching a flowing or flowing stream of water, a person can relieve his nervous and mental stress. What causes this? As far as is known, water does not contain any substances that can give such an effect. Scientists claim that water has the ability to receive and transmit any information, keeping it intact. The past, present and future are dissolved in water. These properties of water have been and are widely used in magic and healing. There are still traditional healers and healers who “whisper into water” and thereby cure diseases. Flowing water constantly takes the energy of the Cosmos and releases it in its pure form into the surrounding near-Earth space, where it is absorbed by all living organisms located within the reach of the flow, since the biofield formed by flowing water is constantly increasing due to the released energy. The faster the water flow moves, the stronger this field. Under the influence of this force, the energy shell of living organisms is aligned, “breakdowns” in the shell of the body (aura) invisible to ordinary people are closed, and the body is healed.

Anomalous properties of water

The first anomalous property of water is boiling and freezing point anomaly: If water - oxygen hydride - H 2 O were a normal monomolecular compound, such as, for example, its analogues in the sixth group of the Periodic Table of Elements D.I. Mendeleev sulfur hydride H 2 S, selenium hydride H 2 Se, tellurium hydride H 2 Te, then in a liquid state water would exist in the range from minus 90 o C to minus 70 o C. With such properties of water, life on Earth would not exist.

“Abnormal” melting and boiling temperatures of water are far from the only anomalies in water. For the entire biosphere, it is extremely important A special feature of water is its ability to increase rather than decrease its volume when freezing, i.e. reduce density. This is the second water anomaly, which is called density anomaly. This special property of water was first noticed by G. Galileo. When any liquid (except gallium and bismuth) transforms into a solid state, the molecules are located closer together, and the substance itself, decreasing in volume, becomes denser. Any liquid, but not water. Water is an exception here too. When cooling, water initially behaves like other liquids: gradually becoming denser, it reduces its volume. This phenomenon can be observed up to +4°C (more precisely up to +3.98°C). It is at a temperature of +3.98°C that water has the highest density and the smallest volume. Further cooling of water gradually leads not to a decrease, but to an increase in volume. The smoothness of this process is suddenly interrupted and at 0°C there is a sharp jump in volume increase by almost 10%! At this moment the water turns into ice. The unique behavior of water during cooling and ice formation plays an extremely important role in nature and life. It is this feature of water that protects all bodies of water on earth - rivers, lakes, seas - from complete freezing in winter, and thereby saves lives.

Unlike fresh water, sea water behaves differently when cooled. It freezes not at 0°C, but at minus 1.8-2.1°C - depending on the concentration of salts dissolved in it. It has maximum density not at + 4°C, but at -3.5°C. Thus, it turns into ice without reaching its greatest density. If vertical mixing in fresh water bodies stops when the entire mass of water is cooled to +4°C, then in sea water vertical circulation occurs even at temperatures below 0°C. The exchange process between the upper and lower layers occurs continuously, creating favorable conditions for the development of animal and plant organisms.

All thermodynamic properties of water differ noticeably or sharply from other substances.

The most important of them is Specific heat anomaly. The abnormally high heat capacity of water makes the seas and oceans a giant temperature regulator of our planet, as a result of which there are no sharp temperature changes in winter and summer, day and night. Continents located near seas and oceans have a mild climate, where temperature changes at different times of the year are insignificant.

Powerful atmospheric currents containing a huge amount of heat absorbed during the process of vaporization, giant ocean currents play an exceptional role in creating weather on our planet.

The heat capacity anomaly is as follows:
When any substance is heated, its heat capacity invariably increases. Yes, any substance, but not water. Water is an exception; even here it does not miss the opportunity to be original: with increasing temperature, the change in the heat capacity of water is anomalous; from 0 to 37°C it decreases and only from 37 to 100°C the heat capacity increases all the time. Within temperatures close to 37°C, the heat capacity of water is minimal. These temperatures are the temperature range of the human body, the area of ​​our life. The physics of water in the temperature range of 35-41°C (the limits of possible, normally occurring physiological processes in the human body) states the probability of achieving a unique state of water, when the masses of crystalline and bulk water are equal to each other and the ability of one structure to transform into another is maximum. This remarkable property of water determines the equal probability of reversible and irreversible biochemical reactions in the human body and provides “easy control” of them.

The exceptional ability of water to dissolve any substance is well known. And here the water demonstrates anomalies unusual for a liquid, and first of all anomalies of dielectric constant of water . This is due to the fact that its dielectric constant (or dielectric constant) is very high and amounts to 81, while for other liquids it does not exceed 10. In accordance with Coulomb’s law, the force of interaction between two charged particles in water will be 81 times less, than, for example, in air, where this characteristic is equal to unity. In this case, the strength of intramolecular bonds decreases by 81 times and, under the influence of thermal motion, the molecules dissociate to form ions. It should be noted that due to its exceptional ability to dissolve other substances, water is never perfectly pure.

One more amazing water anomaly should be mentioned - exceptionally high surface tension. Of all known liquids, only mercury has a higher surface tension. This property is manifested in the fact that water always strives to reduce its surface. Uncompensated intermolecular forces of the outer (surface) layer of water, caused by quantum mechanical reasons, create an external elastic film. Thanks to the film, many objects, being heavier than water, are not immersed in water. If, for example, a steel needle is carefully placed on the surface of the water, the needle will not sink. But the specific gravity of steel is almost eight times greater than the specific gravity of water. Everyone knows the shape of a drop of water. High surface tension allows water to have a spherical shape when free falling.

Surface tension and wetting are the basis for the special properties of water and aqueous solutions, called capillarity. Capillarity is of great importance for the life of flora and fauna, the formation of structures of natural minerals and the fertility of the earth. In channels that are many times narrower than a human hair, water acquires amazing properties. It becomes more viscous, thickens 1.5 times, and freezes at minus 80-70°C.

The reason for the superanomaly of capillary water is intermolecular interactions, the secrets of which are still far from being revealed.

Scientists and specialists know the so-called pore water . In the form of a thin film, it covers the surface of the pores and microcavities of rocks and minerals of the earth's crust and other objects of living and inanimate nature. Connected by intermolecular forces to the surface of other bodies, this water, like capillary water, has a special structure.

Thus, the anomalous and specific properties of water play a key role in its diverse interaction with living and inanimate nature. All these unusual features of the properties of water are so “successful” for all living things that they make water an indispensable basis for the existence of life on Earth.

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Introduction

Water is the most common and widespread substance in our life. However, from a scientific point of view, this is the most unusual, most mysterious liquid. Perhaps only liquid helium can compete with it. But the unusual properties of liquid helium (such as superfluidity) appear at very low temperatures (near absolute zero) and are determined by specific quantum laws. Therefore, liquid helium is an exotic substance. Water in our minds is the prototype of all liquids, and it is all the more surprising when we call it the most unusual. But what makes the water so unusual? The fact is that it is difficult to name any of its properties that would not be anomalous, that is, its behavior (depending on changes in temperature, pressure and other factors) differs significantly from that of the vast majority of other liquids, in which this behavior is similar and can be explained from the most general physical principles. Such ordinary, normal liquids include, for example, molten metals, liquefied noble gases (with the exception of helium), organic liquids (gasoline, which is a mixture of them, or alcohols). Water is of paramount importance in most chemical reactions, in particular biochemical ones. The ancient position of the alchemists - “bodies have no effect until they are dissolved” - is largely true. Humans and animals can synthesize primary (“juvenile”) water in their bodies and form it during the combustion of food products and the tissues themselves. In a camel, for example, the fat contained in the hump can produce 40 liters of water through oxidation. The connection between water and life is so great that it even allowed V.I. Vernadsky to “consider life as a special colloidal water system... as a special kingdom of natural waters.” Water is a familiar and unusual substance. The famous Soviet scientist Academician I.V. Petryanov called his popular science book about water “The Most Extraordinary Substance in the World.” And Doctor of Biological Sciences B.F. Sergeev began his book “Entertaining Physiology” with a chapter about water - “The Substance that Created Our Planet.” Scientists are right: there is no substance on Earth more important for us than ordinary water, and at the same time, there is no other substance of the same type whose properties would have as many contradictions and anomalies as its properties.

Density anomaly

The density anomaly, which is that the density of ice is less than that of liquid water, and the maximum density around 4 C is explained by the internal structure of water. When ice melts, its regular structure is disrupted and some of the complexes are destroyed. In water, along with areas that have a structure similar to the crystal lattice of ice, single molecules appear. The disruption of the regular structure is accompanied by an increase in density and a decrease in volume, since single water molecules fill the cavities that remain in areas with an ice-like structure. As the temperature rises, the action of two factors manifests itself: thermal expansion and disruption of the regular structure of the ice. Thermal expansion, accompanied by a slight increase in volume, is associated with a decrease in the orderliness of the arrangement of molecules. At 4 C these two factors are identical in absolute value, but opposite in direction of action. With a further increase in temperature, the effect of the second factor decreases, the effect of thermal expansion becomes more pronounced and the density of water decreases.

The water density anomaly has a great influence on the planet’s climate, as well as on the life of animals and plants. When the water of rivers, lakes and seas cools below 4, it becomes lighter and does not sink to the bottom, but remains on the surface, where it freezes. At this temperature life is possible. If the density of ice was greater than the density of water, then as the ice formed, it would sink to the bottom and the oceans would completely freeze, since the heat received from the Sun during warm times would not be enough to thaw them.

The anomaly in water density is of great importance for the life of living creatures inhabiting frozen bodies of water. At temperatures below 4 C, surface layers of water do not sink to the bottom, since they become lighter when cooled. Therefore, the upper layers of water can harden, while in the depths of the reservoirs the temperature remains at 4 °C. Under these conditions, life goes on.

Consequently, they try to explain the density anomaly by the highest density of dihydrol water.

What explains the anomaly in water density?

One explanation for the anomaly in the density of water is that it is attributed to the tendency for its molecules to associate, which form various groups [H2O, (H2O) 2, (H2O) 3], the specific volume of which

is different at different temperatures and the concentrations of these groups are different, therefore, their total specific volume is different.

The first of these means that density anomalies resulting from movement do not create a heat flow through the lower grove. At the upper boundary, the density is specified, and at the shore (x 0) the normal component of the horizontal heat flux is considered equal to zero. The velocities and and and on the shore should vanish due to the conditions of non-flow and sticking. The hydrostatic approximation, however, simplifies the dynamics so much that the no-slip condition for and; cannot be completed.

Tertiary and secondary alcohols are characterized by an anomaly in vapor density at high temperatures (determination according to B. Tertiary alcohols (up to Cj2) give only half the molecular weight at the boiling point of naphthalene (218e), due to their decomposition into water and alkylenes; secondary alcohols (up to C9 ) exhibit the same anomaly, but.

The positive sign of work must be attributed to the anomaly in water density.

If, as Grebe claims, the work of Sainte-Clair Deville contributed, on the one hand, to the explanation of the observed anomalies in vapor densities and thereby, albeit indirectly, confirmed Avogadro’s theory, then, on the other hand,

On the other hand, these works served as a stimulus for the study of chemical affinity, as they contributed to elucidating the nature of certain reactions.

For water, equation (64) gives correct results up to temperature 4, since it is known to have a density anomaly. At 4, the density of water is greatest; below 4, a complex density distribution is observed, which is not taken into account by this equation.

By virtue of (8.3.56), the parameter X is a measure of the ratio (L / LH) 2 and inequality (8.3.19 a) simply means that the density anomalies created by the pressure are mixed on a scale small compared to L.

In the presence of underlying stratification, the positive rotor of shear wind stress and the associated vertical motion in the interior region creates a positive density anomaly throughout that region, to which is added the density anomaly due to heat gain at the surface.

If the bonds inside polyhedra are much stronger than between polyhedra, then only these latter will be disordered in the melt, so that units in the form of polyhedra will exist in the melt. Some density anomalies in liquid Al-Fe alloys seem to support this hypothesis.

The formulation of the problem for the stability of such a ground state will be given for the case of zonal flow in the atmosphere. The case of the ocean can be considered as a special case of the problem for the atmosphere in all respects to the formulation of the problem and is obtained by simply replacing the standard density profile ps (z) with a constant value of density and replacing the anomaly of the atmospheric potential temperature in the anomaly of the ocean density, taken with a minus sign.

Increasing pressure shifts the maximum density of water towards lower temperatures. Thus, at 50 atm, the maximum density is observed around 0 C. Above 2000 atm, the water density anomaly disappears.

Thus, over a wide temperature range, the most energetically stable compound of hydrogen and oxygen is water. It forms oceans, seas, ice, steam and fog on Earth; it is found in large quantities in the atmosphere; in rock layers, water is represented in capillary and crystalline hydrate forms. Such prevalence and unusual properties (anomaly in the density of water and ice, the polarity of molecules, the ability for electrolytic dissociation, the formation of hydrates, solutions, etc.)

make water an active chemical agent, in relation to which the properties of a large number of other compounds are usually considered.

Liquids tend to expand noticeably when heated. Some substances (for example, water) have a characteristic anomaly in the values ​​of the isobaric expansion coefficient. At higher pressures, the maximum density (minimum specific volume) shifts towards lower temperatures, and at pressures above 23 MPa, the density anomaly in water disappears.

This estimate is encouraging because the value of Ba is in good agreement with the observed thermocline depth, which varies from 800 m in mid-latitudes to 200 m in the tropical and polar zones. Since the depth 50 is significantly less than the depth of the ocean, it seems reasonable to consider the thermocline as a boundary layer; in accordance with this, when setting the boundary condition at the lower boundary, we can assume that the temperature at depths greater than the BO asymptotically tends to some horizontally homogeneous distribution. Since the scale of z is already equal to D, it is convenient to move the origin to the surface and measure z from the ocean surface. Thus, at z - - the density anomaly should decay and should tend to an as yet unknown asymptotic value, just as the vertical velocity created at the lower boundary of the Ekman layer cannot be specified a priori.

Permanent UE should be determined from the conditions on the ground. In the hydrostatic layer, due to large density gradients created by vertical movement (La S / E), y is much larger than vj in magnitude. At the same time, v must satisfy the no-slip condition for f x O. Vn are equal to zero and, therefore, itself. This difficulty is resolved if we remember that in the internal region, vertical mixing of density balances the effect of vertical movement, and in the hydrostatic layer, the density anomaly created by vertical movement is balanced only by the effect of horizontal mixing. Thus, there must be an intermediate region between the interior region and the hydrostatic layer, in which vertical and horizontal diffusion are equally important. As (8.3.20) shows, this region has a horizontal scale Lff, so that A calculated with this scale is equal to unity.

As is known, water, when heated from zero temperature, contracts, reaching its smallest volume and, accordingly, its highest density at a temperature of 4 C. Researchers from the University of Texas have proposed an explanation that takes into account not only the interaction of nearby water molecules, but also more distant ones. In all 10 known forms of ice and in water, the interaction of nearby molecules occurs in the same way. The situation is different with the interaction of more distant molecules. In the liquid phase, in the temperature range where there is an anomaly in density, the state with a higher density is more stable. The density-temperature curve that the scientists calculated is similar to that observed for water.

Pure water is transparent and colorless. It has neither smell nor taste. The taste and smell of water are given by impurity substances dissolved in it. Many physical properties and the nature of their changes in pure water are anomalous. This refers to the melting and boiling temperatures, enthalpies and entropies of these processes. The temperature variation in the change in water density is also anomalous. Water has its maximum density at 4 C. Above and below this temperature, the density of water decreases. During solidification, a further sharp decrease in density occurs, so the volume of ice is 10% greater than the equal volume of water at the same temperature. All of these anomalies are explained by structural changes in water associated with the formation and destruction of intermolecular hydrogen bonds with temperature changes and phase transitions. The anomaly in water density is of great importance for the life of living creatures inhabiting frozen bodies of water. At temperatures below 4 C, surface layers of water do not sink to the bottom, since they become lighter when cooled. Therefore, the upper layers of water can harden, while in the depths of the reservoirs the temperature remains at 4 C. Under these conditions, life continues.

Properties of liquids. Surface tension

The molecules of a substance in a liquid state are located almost close to each other. Unlike solid crystalline bodies, in which molecules form ordered structures throughout the entire volume of the crystal and can perform thermal vibrations around fixed centers, liquid molecules have greater freedom. Each molecule of a liquid, just like in a solid, is “sandwiched” on all sides by neighboring molecules and undergoes thermal vibrations around a certain equilibrium position. However, from time to time any molecule may move to a nearby vacant site. Such jumps in liquids occur quite often; therefore, the molecules are not tied to specific centers, as in crystals, and can move throughout the entire volume of the liquid. This explains the fluidity of liquids. Due to the strong interaction between closely located molecules, they can form local (unstable) ordered groups containing several molecules. This phenomenon is called short-range order (Fig. 1)

The water molecule H2O consists of one oxygen atom and two hydrogen atoms located at an angle of 104°. The average distance between steam molecules is tens of times greater than the average distance between water molecules. Due to the dense packing of molecules, the compressibility of liquids, i.e., the change in volume with a change in pressure, is very small; it is tens and hundreds of thousands of times less than in gases. For example, to change the volume of water by 1%, you need to increase the pressure approximately 200 times. This increase in pressure compared to atmospheric pressure is achieved at a depth of about 2 km.

Liquids, like solids, change their volume with changes in temperature. For not very large temperature intervals, the relative change in volume DV / V0 is proportional to the change in temperature DT:

Coefficient b is called the temperature coefficient of volumetric expansion. This coefficient for liquids is tens of times greater than for solids. In water, for example, at a temperature of 20 ° C. 2·10-4 K-1, at steel stand? 3.6·10-5 K-1, for quartz glass vkv? 9·10-6 K-1.

has an interesting and important anomaly for life on Earth. At temperatures below 4 °C, water expands as the temperature decreases (at< 0). Максимум плотности св = 103 кг/м3 вода имеет при температуре 4 °С.

The most interesting feature of liquids is the presence of a free surface. Liquid, unlike gases, does not fill the entire volume of the container into which it is poured. An interface is formed between liquid and gas (or vapor), which is in special conditions compared to the rest of the liquid. Molecules in the boundary layer of a liquid, unlike molecules in its depth, are not surrounded by other molecules of the same liquid on all sides. The forces of intermolecular interaction acting on one of the molecules inside a liquid from neighboring molecules are, on average, mutually compensated. Any molecule in the boundary layer is attracted by molecules located inside the liquid (the forces acting on a given liquid molecule from gas (or vapor) molecules can be neglected). As a result, a certain resultant force appears, directed deep into the liquid. Surface molecules are drawn into the liquid by forces of intermolecular attraction. But all molecules, including molecules of the boundary layer, must be in a state of equilibrium. This equilibrium is achieved by slightly reducing the distance between the molecules of the surface layer and their nearest neighbors inside the liquid. As can be seen from Fig. 1, as the distance between molecules decreases, repulsive forces arise. If the average distance between molecules inside the liquid is equal to r0, then the molecules of the surface layer are packed somewhat more densely, and therefore they have an additional reserve of potential energy compared to the internal molecules (see Fig. 2). It should be borne in mind that due to the extremely low compressibility, the presence of a more densely packed surface layer does not lead to any noticeable change in the volume of the liquid. If a molecule moves from the surface into the liquid, the forces of intermolecular interaction will do positive work. On the contrary, in order to pull a certain number of molecules from the depth of the liquid to the surface (i.e., increase the surface area of ​​the liquid), external forces must perform positive work DAex, proportional to the change DS of the surface area:

The coefficient y is called the surface tension coefficient (y > 0). Thus, the coefficient of surface tension is equal to the work required to increase the surface area of ​​a liquid at constant temperature by one unit.

In SI, the coefficient of surface tension is measured in joules per square meter (J/m2) or in newtons per meter (1 N/m = 1 J/m2).

Consequently, the molecules of the surface layer of a liquid have excess potential energy compared to the molecules inside the liquid. The potential energy Er of the liquid surface is proportional to its area:

water anomaly density tension

It is known from mechanics that the equilibrium states of a system correspond to the minimum value of its potential energy. It follows that the free surface of the liquid tends to reduce its area. For this reason, a free drop of liquid takes on a spherical shape. The liquid behaves as if forces acting tangentially to its surface are contracting (pulling) this surface. These forces are called surface tension forces.

The presence of surface tension forces makes the surface of a liquid look like an elastic stretched film, with the only difference that the elastic forces in the film depend on its surface area (i.e., on how the film is deformed), and the surface tension forces do not depend on the surface area liquids.

Some liquids, such as soapy water, have the ability to form thin films. Well-known soap bubbles have a regular spherical shape - this also shows the effect of surface tension forces. If a wire frame, one of whose sides is movable, is lowered into a soap solution, then the entire frame will be covered with a film of liquid (Fig. 3).

Surface tension forces tend to reduce the surface of the film. To balance the movable side of the frame, an external force must be applied to it. If, under the influence of force, the crossbar moves to Dx, then work will be done DAvn = FvnDx = DEp = yDS, where DS = 2LDx is the increment in the surface area of ​​​​both sides of the soap film. Since the moduli of forces and are the same, we can write:

Thus, the surface tension coefficient y can be defined as the modulus of the surface tension force acting per unit length of the line delimiting the surface.

Conclusion

Water is the most studied substance on Earth. But it is not so. For example, scientists have recently discovered that water can carry information that is erased if the water is first frozen and then thawed. Also, scientists cannot explain the fact that water is able to perceive music. For example, when listening to Tchaikovsky, Mozart, Bach and subsequent freezing, crystals of the correct shape are formed, and after hard rock something shapeless is formed. The same thing is observed when comparing Mother Teresa and Hitler; the words “love”, “hope” and the words “fool”. In addition, scientists compared the energy of water, and it turned out that water from the table mountains of Africa is much more charged than tap water, and water in huge bottles, no matter how pure it is, is dead. Also, no matter how paradoxical it may be, combustion is impossible without water! After all, water is contained everywhere and this says a lot. If you remove all the water from gasoline, it will completely stop burning. And even the water itself is on fire!!! The truth is not so intense, but still the fact remains a fact.

Many people know that water can form a very stable compound with oil, which is not suitable for processing. But Russian scientists have come up with a way to separate them. To do this, the oil substrate was exposed to an electromagnetic field for a week. And after its expiration, it divided into oil and water. But the most interesting thing is that the frequency of the field was equal to the frequency of the biocurrents of the heart.

Hydrosphere is the water shell of the Earth: 3/4 of the surface of the planet is covered with water. The total volume of water reserves is 1,400,000,000 km3, of which:

97% - salt water of the World Ocean;

2.2% - cover glaciers and mountain and floating ice;

Detailed geological measurements have shown that over 80-100 million years, all of the earth's land is carried away by water flow into the World Ocean. The driving force of this process is the water cycle in nature - one of the main planetary processes.

Under the influence solar energy The world's oceans evaporate about 1 billion tons of water per minute. Rising into the cold upper layers of the atmosphere, water vapor condenses into microdroplets, which gradually enlarge and form clouds. The average lifespan of a cloud is 8-9 days. For that

time, the wind can move it 5-10 thousand km, so a significant part of the clouds ends up above land.

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