One and the same speech in the world is stale in the minds of restless minds, maybe in different countries. For example, water can look like water, in the idea of a solid body - ice, and look like gas - water vapor.
- Qi become called aggregate camps of speech.
Molecules of speech in different aggregate mills are in no way one and the same. A specific aggregate camp is determined by the distribution of molecules, as well as by the nature of their movement and interaction with each other.
Gas - between molecules is significantly larger than the size of the molecules themselves. Molecules in rіdinа and in solid tіlі roztashovanі are close to one to one. Hard bodies are closer.
To change the aggregate mill of the body, It is necessary for you to revive the deak's energy. For example, to convert water into steam, you need to heat it up. Sob the couple became water again, it is to blame for energy.
Transition from a solid state to a rare one
The transition of speech from a solid state is rarely called melting. In order for the body to begin to melt, it must be heated to the right temperature. The temperature at which speech melts, called the melting point of speech.
Skin speech has a melting point. At Yakihos, the tіl won't be too low, for example, at the Krigi. And in yakihos til the melting point is too high, for example, it’s cold. Vzagali, melting of the crystalline body is a folding process.
Ice melting schedule
Below, on a small scale of representations, is a graph of the melting of a crystalline body, near different ice.
- The graph shows the temperature of the ice at the time it is being heated. The temperature is shown on the vertical axis, and the hour on the horizontal axis.
From the graph, the temperature of the ice on the back was -20 degrees. Year of yoga began to heat up. The temperature started to rise. Dіlyanka AV tse dіlyanka heating ice. In an hour, the temperature increased to 0 degrees. This temperature is taken into account by the melting temperature of ice. Over the course of the temperature, the ice melted, but at the same temperature the temperature ceased to grow, although at the same temperature the ice continued to be heated. Dіlyantsі melting vіdpovіdaє dіlyanka SS on the schedule.
Then, if all the ice melted and turned into the motherland, the temperature of the water began to rise again. This is shown on the graph with the change C. To ensure that the whiskers work, so that the temperature of the body does not change during the melting hour, all the energy that comes, go afloat.
Zbіlshennya obyagu lead for її frozen mає value in nature. Due to the smaller ice thickness, it is flooded from the water thickness (at 0 °С the ice thickness is 900 kg/m 3 and the water is 1000 kg/m 3) ice floats on water. Mayuchi filthy heat conduction, the ball of ice protects the water, which is under it, in view of the cooling, it freezes. To that riba and others are alive, that by the water, do not die under the hour of frost. Yakby ice was sinking, then not even deep water would freeze through the waters through the winter.
With the expansion of freezing water in a closed vessel, the majestic forces are blamed, building a thick-walled chive. It is easy to make a similar meal with a bun filled with water up to the neck and exposed to frost. On the surface of the water, a cork is established, which clogs the plaque, and when the water expands, it freezes, the dance will be torn.
Freezing water in the cracks of the mountainous pores leads to the destruction of the future.
The building of water expands at firmness, it is necessary to repair it under the hour of laying pipes for water supply and sewerage, as well as water scorching. In order to escape the rise of the water during the freezing hour, the underground chimneys must be laid down on such a depth, so that the temperature does not fall below 0 ° C. The outer parts of the pipes are to be covered with heat-insulating materials for the winter hour.
Temperature deposit of melting point
As the melting of the speech is accompanied by a greater degree of commitment, then the temperature of the melting of the speech rises due to the greater pressure. You can explain it this way. The squeezing of speech (with an increase in the callous pressure) shifts the increase in the difference between molecules and, also, the increase in the potential energy of the interaction of molecules, which is necessary for the transition to a rare state. To bring the body to a higher temperature, the potential energy of the molecules does not reach the necessary value.
As the melting of the speech is accompanied by changes in the contract, then with the increase in the current pressure, the temperature of the melting of the speech decreases.
So, for example, ice with a vice of 6 10 7 Pa melts at a temperature of -5 ° C, and with a vice of 2.2 10 8 Pa, the melting temperature of ice reaches -22 ° C.
The lowering of the melting point of ice with the increased pressure is well illustrated by evidence (Fig. 8.34). Nylon thread to pass through ice, not ruining yoga. On the right, in the fact that the threads on the lead of the thread are tied to the weight of the significant vice under it. Water, winding with threads, freezes at once.
Lost point
The homeland can be rebuked in Rivnovaz with its own couple (full couple). Figure 6.5 (div. § 6.3) shows the amount of pressure on the increased wager versus temperature (curve AB), taken experimentally. So, as the boiling of the spring comes from the vise, which is more expensive than the vice of the high bet, then the curve gives the temperature of the boiling in the vise. The area that lies below the curve AB, conforms to a gas mill, and more to a rare one.
Kristalіchnі tіla melt at the same temperature, at which the solid phase is rare. The melting temperature is deposited in a vise. You can show the same little thing, demonstrating the coldness of the boiling temperature in the vise.
On the little one 8.35 crooked TC characterizes the staleness of the boiling point in the vise. It will end at the point Before, in the case of critical temperature, since the higher temperature of the homeland cannot be substantiated. Levishe curve TC curve behind the experimental points TS the temperature of melting temperature is lower in vice (higher, so that the solid phase is subject to lower temperatures, lower is rare). Offensive curves are tinted at point T.
What will be with the speech at a temperature below the temperature t t p , vidpovidnoy point T? A rare phase beyond the temperature range is already impassable. Speech will either be in a solid state, or in a gas-like state. curve VID(Div. fig. 8.35) in vіdpovіdaє іvnо important stanam tіlo - gas, scho vikaє pіd hour of sublimation оf solid іl.
Three curves CT, TKі VID to divide the phase plane into three regions, in which speech can be in one of three phases. The curves themselves describe the equal parts of the motherland - steam, the motherland - hard body and hard body - steam. Use only one point T, in yakіy usі three phases are changed in rіvnovazi. Tse i є triyna point.
Each point indicates the same temperature value for the vise. You can accurately determine, and won't be one of the most important reference points when using the absolute temperature scale. For water, the absolute temperature of the loss point is assumed to be equal T tr = 273.16 K, or t t p = 0.01 °C.
At 8.35, a phase diagram of water is shown, in which the melting point changes with increasing pressure. For the best speeches, it's crooked TS heeled at the opposite side of the line exactly vertically, to pass through the point T.
For example, this looks like a phase diagram for carbon oxide 2 . Temperature of CO 2 loss point t tr \u003d -56.6 ° С, and vice p tr \u003d 5.1 atm. Therefore, with extreme atmospheric pressure and temperatures close to room temperature, carbonic acid cannot survive at a rare station. The solid phase 2 is called dry ice. The wine may be at a very low temperature and do not melt, but immediately evaporate (sublimation).
The change is obligatory at melting and hardening without intermediary due to the coldness of the melting temperature in the vise. In the most important speeches, the melting point increases with pressure. At the driver of that іnshih speeches won, navpaki, decrease. For the baggers of the Earth at high geographical latitudes, this is a great boon.
Ісnuє single point on the diagram r-T (continuous point), where all three phases of speech are changed by equal.
At the end, the significance of solid state physics is significantly greater in the development of technology and civilization in the beginning.
The people have always victoriously and victoriously hardened the body. Although earlier the physics of solid bodies did not follow the development of technology, which is based on absolute knowledge, now the camp has changed. Theoretical investigations begin to lead to the creation of solid bodies, the power of which is absolutely independent and it would be impossible to take them away by the method of "trials and pardons". Vinahіd transistors, about how to go far away, the brightest example of that, like the understanding of the structure of solid bodies, led to a revolution in all radio engineering.
The creation of materials from the tasks of mechanical, magnetic and other powers is one of the main directions of solid state physics. Approximately half of the physicists of the world practice at the same time in the field of solid state physics.
Skin view that water can be used in nature in three aggregate mills - solid, rare and gaseous. When melted, solid ice transforms into the motherland, and when heated further, the motherland evaporates, satisfying the water vapor. How about melting, crystallization, evaporation and condensation of water? At such a temperature, how does steam settle? We'll talk about them in this article.
It is impossible to say that water vapor and ice are rarely seen in everyday life. However, let's widen the most - a rare camp - zvichayna water. Fahіvtsі z'yasuvali that on our planet there are over 1 billion cubic kilometers of water. Prote no more than 3 million km 3 of water lie fresh water. There is a large amount of fresh water to “rest” at the ice rinks (about 30 million cubic kilometers). It is far from easy to melt the ice of such majestic shaves. Reshta is salty water, which the seas of the Light Ocean should lie in.
Water otchusnu chasnu people everywhere, pіd іn the hour bіlshostі schodennykh procedures. It is rich who cares that the reserves of water are not depleted, and the people are able to conquer the resources of the Earth's hydrosphere. However, it is not so. The water resources of our planet are step by step being used up, and already for hundreds of rocks in the fresh water of the Earth, we can run out of water. Therefore, absolutely skinned people need to be put to fresh water and save money. Adzhe navit at our time to establish powers, de store water catastrophically small.
Domineering leadership
First, let's talk about the temperature of ice tanning, let's take a look at the main powers of the unique homeland.
Otzhe, the waters of the taman are so powerful:
- Visibility of colors.
- Seeing the smell.
- Vіdsutnіst relish (prote yakіsna pitna water maє priemny relish).
- transparency.
- Fluidity.
- Building diversity of speech (for example, salt, meadows toshcho).
- Water does not have a damp, constant form, and it’s built to fill up the form of a judge, in a yak, it’s sipped.
- The building is cleared by the sight of filtering.
- Under an hour of heating, the water expands, and when it is cold, it shrinks.
- Water can evaporate, turning into a steam, and freeze, making crystalline ice.
This list has the main powers of the water. Now let's take a look at what are the features of the solid aggregate steel of speech, and at the same temperature, ice.
Lіd - tse hard crystalline speech, yak mає dosit unstіyku structure. Vіn, yak i water, prozory, not maє kolor that smell. So lid may be so powerful, like crying and slimy; vin cold on dotik.
Snow is also frozen water, prote maє fluff structure and maє white color. The very snіg shoroku vypadє in the greater kraїn svіtu.
Like a snig, so a lіd - in a land of unstoppable speech. To melt the krieg, it is not necessary to apply special zusil. When will vin start tanuti?
In nature, solid ice is only available at temperatures of 0 °C and below. As the temperature of the current medium rises and becomes more than 0 ° C, the ice begins to melt.
At a temperature of ice melting at 0 ° C, another process is observed - freezing, or crystallization, rare water.
This process can be predicted for all bagmen with a moderately continental climate. Vzimku, if the temperature on the street drops below 0 ° C, it often falls snow, which is not the same. And the water that was found on the streets freezes, turning into hard snow or ice. Hanging can help the return process. The temperature of the navkolyshny middle ground rises, to that the ice and snow melt, satisfying the numerical kalyuzhi and the ford, as it can be considered as the only minus of the spring warming.
In this way, it is possible to grow visnovok, which at a certain temperature begins to melt ice, at the same temperature, the process of freezing water begins.
Amount of warmth
Such a science like physics often wins the understanding of the amount of heat. This value shows the amount of energy required for heating, melting, crystallization, boiling, evaporation or condensation of various speeches. Moreover, leather from the listed processes may have its own peculiarities. Let's talk about those, how much heat for heating ice is needed in great minds.
To heat the krieg, it is necessary to drink rosemary and rosemary. For which one needs a certain amount of heat, it is necessary for the melting of solid speech. The heat of additional oil production of ice for the consumed heat of its melting (330-345 thousand Joules / kg) and is measured in Joules. Suppose we are given 2 kg of solid ice. In this order, we need to drink yogo rose: 2 kg * 340 kJ / kg = 680 kJ.
Therefore, we need to heat the water, which has been settled. The amount of warmth for which process of unraveling will be troch folded. For whom it is necessary to know the pochatkov and kіntsev temperature of the water that is heated.
Also, let's say that we need to heat the water, which was the result of melting ice, by 50 ° C. Tobto the difference between the cob and end temperatures = 50 ° C (cob water temperature - 0 ° C). Then multiply the temperature difference by the weight of the water and your pet's heat capacity, which is 4 200 J * kg / ° C. That is the amount of heat, the necessary heating of water, \u003d 2 kg * 50 ° C * 4 200 J * kg / ° C \u003d 420 kJ.
Todi it is necessary that for melting ice and further heating of water, which we need: 680,000 J + 420,000 J = 1,100,000 Joules, or 1.1 Megajoules.
Knowing that for such a temperature of ice, it is possible to overcome the impersonal difficult tasks of physics or chemistry.
At the end
Later, at this statute, they found out facts about water and about two aggregate steels - hard and rare. Water vapor, however, is not a lesser object for marriage. For example, our atmosphere has approximately 25*1016 cubic meters of water vapor. Until then, on the vіdmіnu vіd freezing, viparovuvannya vіdbuvaєtsya for any temperature and quicken at її її navnіnі or for obviousness of the wind.
We found out that for a certain temperature, ice and water rarely freezes. We always need such facts in everyday life, shards of water leave us here. Water, especially fresh water, is the ultimate resource of the Earth and will require extensive installation.
melting
melting- This is the process of transforming speech from a firm stand in a row.
Be careful to show that if there is more ice, if, for example, a temperature of 10 ° C is left in a warm room, then the temperature will rise. At 0 ° C, the ice is more likely to melt, and the temperature at this temperature does not change until all the ice is transformed into the motherland. If the temperature of the water, which has settled into the ice, will rise.
Tse means that crystal bodies, lie down to ice, melt at a singing temperature, how to call melting point. It is important that during the melting process, the temperature of the crystalline speech and the mother tongue, which took place in the process of melting, becomes permanent.
In the described case, when the ice was taken away from the heat, its internal energy increased the balance of the average kinetic energy of the molecules. Then the ice melted, but its temperature did not change, even though the ice took away some warmth. Later, this internal energy increased, not just the kinetic energy, but the potential energy of the interaction of molecules. The summoned energy is spent on the destruction of the crystal gates. In a similar rank, the melting of some kind of crystalline body is observed.
Amorphous bodies have no melting point. When the temperature rises, the stench progressively softens, the docks do not transform into the motherland.
Crystallization
Crystallization- This is the process of the transition of speech from a rare state to a firm state. Cooling down, the homeland gives the deak a little warmth to the needy wind. Whom will change the internal energy of the shells, the change in the average kinetic energy of the molecules. At the same temperature, the process of crystallization will be revealed, but during the hour of the process, the temperature of the speech will not change until the entire speech has passed into a solid state. This transition is accompanied by a vision of a singing quantity of warmth and a change in the internal energy of the speech of the shell of a change in the potential energy of the interaction of the molecules.
In this way, the transition of speech from a rare state to a hard one becomes dependent on the singing temperature, called the temperature of crystallization. Tsya temperature is filled with a constant stretch of the melting process. There is a higher temperature of melting of speech.
A graph of the temperature of solid crystalline speech is drawn on the little one every hour in the process of heating from room temperature to the temperature of melting, melting, heating of speech in a rare station, cooling of a rare speech, crystallization and further cooling no speech in a solid state.
Pitoma heat of fusion
Rіznі kristalіchnі chіchini mаyut rіznu budova. Apparently, in order to blast the crystal lattice of a solid body at the temperature of the first melting, it is necessary to change the amount of heat.
Pitoma heat of fusion- the whole amount of warmth, as it is necessary to renew 1 kg of crystalline speech, in order to turn it into the motherland at the melting temperature. Dosvid shows that the heat of melting is good nourished by the warmth of crystallization .
Pitoma heat of fusion is denoted by the letter λ . Unit of heat of melting - [λ] = 1 J/kg.
The value of the heat of melting of crystalline speeches is shown in the table. The heat of melting of aluminum is 3.9*105 J/kg. Tse means that for melting 1 kg of aluminum at a melting temperature, it is necessary to increase the amount of heat 3.9 * 10 5 J. To this value, it is more important to increase the internal energy of 1 kg of aluminum.
Schob calculate the amount of heat Q, necessary for melting speech with a mass m taken at the melting point, following the heat of melting λ multiply by the mass of speech: Q = λm.