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There are 2 beneficial ones:
1.The winter in the north is cold, in order to properly preserve the vegetables, a few buckets of water are put in the vegetable cellar, and the heat can be released when the water freezes, and the temperature in the cellar is not too low.
2.There is also a use in the hospital:"In the process of coagulation and exothermy, gypsum dilates blood vessels and enhances anti-inflammatory effects"An example of a patient suffering from facial acne.
An example of the adverse effects of solidification and exothermic is found in relation to low-heat cement:
Normally, cement generates heat when it reacts chemically with water to solidify. It has been determined that its temperature can rise to about 50 degrees Celsius. Ferroconcrete.
Initially, the exothermic phenomenon expands the volume of the building, and when it cools down, it immediately undergoes a shrinkage reaction. Due to the cold of the outer perimeter of the building.
However, the speed is faster, and the inner edge is slower, and such a "time difference" can easily form cracks and fractures in the building. In order to overcome this problem, Japanese researchers envisaged that the amount of heat emitted by cement as it solidified would be less than half of that of ordinary ones. They add a large amount of calcium silicate to the general cement, so that the "hotbed" of forming cracks is removed, and the quality of the cement can be greatly improved, the longer the time, the higher the strength.
Scholars generally agree that low-calorie cement is a promising material and a new bright spot in the construction world.
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If the temperature rises, if a lot of heat is released, it will burn people; The state is changed, solidified into a large block, and it will also cause inconvenience to transportation.
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lead to insecurity; leading to disasters; inconvenience to people's lives; reduced soil fertility; Climate impact (2) Suggestion: biogas production; making fertilizers; Paper; make feed; Smash. Liquefaction Exothermic 4
Solidification Specific heat capacity 5Ninghua endothermic 6Water Vapor Wooden Stopper Water Vapor Mechanical Energy Water Vapor Direction.
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Question 1: Is coagulation endothermic or exothermic? Because solidification occurs when the outside temperature is relatively low, and the heat flows from the high-temperature object to the low-temperature object, the heat flows from the object to the external environment at this time, and the heat is released. Over, look.
Question 2: Solidification is heat absorption and dust posture is heat release, thank you The word more is heat release, and the word less is heat absorption.
Question 3: Is liquefaction, sublimation, condensation, vaporization, melting, and solidification endothermic or exothermic Melting and solidification: Veva leaching q=1
Vaporization and liquefaction.
Sublimation and condensation.
Sublimation, vaporization, melting into endothermy.
Coagulation, liquefaction, coagulation for exothermics.
Question 4: Melting and solidifying? Melt embedding and solidification are both changes in the state of matter.
The process by which a substance changes from one state to another is called a change in the state of matter.
Melting: The phenomenon of a substance changing from a solid state to a liquid state. pre-album (endothermic is required for the melting process).
Coagulation: The phenomenon of a substance changing from a liquid state to a solid state. (The solidification process requires exothermy).
Crystalline and amorphous.
Solids with a fixed melting temperature are called crystals, and solids without a fixed melting temperature are called amorphous.
Melting point: The temperature at which the crystal melts is called the melting point. (Amorphous has no melting point).
Freezing point: The temperature at which the crystal solidifies is called the freezing point. (Amorphous has no freezing point).
Conditions for crystal melting:1The temperature reaches the melting point, 2Absorbs heat continuously.
Conditions for crystal solidification:1The temperature is reduced to the freezing point, 2Heat is released continuously.
Question 5: Is solidification endothermic or exothermic? Exothermic.
Question 6: Melt solidification, vaporization, liquefaction, sublimation, condensation Are these endothermic or exothermic? Does the endothermic and exothermic temperature increase or decrease?
Why? Melt sublimation, gasification, endothermy, solidification, liquefaction, condensation and exothermy. In general, the endothermic temperature increases and the exothermic temperature decreases, which means that the kinetic energy of endothermic molecules increases, the temperature increases, the kinetic energy of exothermic molecules decreases, and the temperature decreases.
In the above six processes of crystal occurrence, the temperature does not change, and the kinetic energy of the molecule does not change, and the potential energy increases.
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Categories: Education, Science, >> Science & Technology.
Problem description: It is best to have the perspective of the internal energy of the molecular branch nucleus from multiple angles.
Analysis: The melting process is the melting process, which is an endothermic process.
The phase transformation process of a substance, such as a nucleus, from a solid phase to a liquid phase. Under a certain pressure, the solid (crystal) must be heated to a certain temperature (melting point) before it can be melted, and the temperature does not change during the melting process, and heat is absorbed from the outside. The heat absorbed by the melting of a unit mass crystal into a liquid is called the latent heat of melting, or heat of fusion for short.
The melting of a crystal is the process in which the lattice particles are excavated from a regular arrangement to a disordered state, and the heat of fusion is the energy required to destroy the lattice structure, which can be used to measure the binding energy of the crystal.
The melting point of different crystals is different, and the melting point of the same crystal is also related to the pressure during melting. The curve that represents the relationship between melting point and pressure on the P-T diagram is called the melting curve, which is the dividing line between the solid and liquid phases, and the points on the curve represent the various states of the coexistence of the solid and liquid phases in equilibrium. Most crystals expand in volume when melted, and the melting point decreases as the pressure increases.
The melting point is also closely related to the purity of the crystal, and a small amount of impurities can often significantly reduce its melting point, and the melting point of the alloy is often lower than the lowest melting point of each metal component in it.
The melting of amorphous solids such as glass, paraffin, resin, asphalt, plastics, etc., does not take place at a specific temperature and has no melting point to speak of. They gradually soften as the temperature rises during the melting process and eventually turn into a liquid.
Solidification is the opposite...
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Brain teaser – what freezes when heated?
Proteins become inactive when exposed to heat, resulting in coagulation, such as eggs. But wouldn't it be too easy to make a brain teaser?
I ask you: What solidifies when heated?
Eggs! Hope! What does heating solidify!!
Asked again. What is the thing that solidifies when heated?
The most common is protein, such as egg white.
Principle: Heating a protein solution close to the isoelectric point can cause the protein to coagulation and precipitate. Heating is first of all to denature the protein by heating, the regular peptide chain structure is opened into a loose irregular structure, the asymmetry of the molecule increases, the hydrophobic group is exposed, and then condenses into a gel-like protein block.
As in hard-boiled eggs, the yolk and egg white are solidified
The denaturation, precipitation, and coagulation of proteins are closely related to each other. However, proteins do not necessarily precipitate after denaturation, denatured proteins only precipitate near the isoelectric point, and precipitated denatured proteins do not necessarily coagulate. For example, after a protein is denatured by a strong acid or alkali, it is still soluble in a strong acid or a strong decrease because the protein particles carry a large amount of charge.
However, if the pH of the strong base and strong acid solution is adjusted to the isoelectric point, the denatured protein will condense into a flocculent precipitate, and if this floc is heated, the molecules will be coiled with each other and become a relatively strong clot.
What is the thing that solidifies when heated?
Good question, what will be melted by heat reduction, there is a contradiction in your question, and the contradiction is the bottomless pit that human beings have brought on themselves.
What is the thing that solidifies when heated?
Good question, what will be melted by heat reduction, there is a contradiction in your question, and the contradiction is the bottomless pit that human beings have brought on themselves.
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1 Put a few buckets of water in the vegetable cellar in the northern winter, so that the vegetables will not freeze 2 It is not cold when it snows, but it is cold after the snow (Snow is formed by the solidification of water droplets in the air) 3 The unsolidified wax oil solidifies slowly in a high temperature environment than in a low temperature environment In general, when the temperature of the object is higher than the ambient temperature, it will release heat, and its own temperature will also drop When it is lowered to a certain temperature, it will solidify (such as water will solidify into ice at minus degrees Celsius) This is what we often call "condensation cover renting and releasing heat"
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Hello! 1 Put a few buckets of water in the vegetable cellar in the northern winter, so that the vegetables will not freeze 2 When it snows, it is not cold and it is cold after the snow (snow is formed by the solidification of water droplets in the air) 3 The unsolidified wax oil solidifies slowly in a high temperature environment than in a low temperature environment In general, when the temperature of the object is higher than the ambient temperature, it will release heat, and its own temperature will also drop When it is lowered to a certain temperature, it will solidify (for example, water will solidify into ice at minus degrees Celsius) This is what we often call "coagulation and exothermy".
After the concrete of the dam body is poured, with the development of cement setting and hardening, a large amount of hydration heat will be released, which will increase the internal temperature of the concrete. Over time, the internal temperature gradually decreases due to the gradual dissipation of heat. At the same time, the volume of concrete is also constantly changing, when the concrete is constrained by the foundation or adjacent pouring block, it will reduce the safety factor of hydraulic buildings, adversely affect stability, according to the experience of dam building at home and abroad, the temperature control of dam body concrete is to prevent cracks in large volume concrete, and ensure the effective method of concrete quality.
The main methods of temperature control of dam concrete are: reducing the calorific value of concrete; reduce the pouring temperature of concrete; dissipate the heat of the pouring block; layered and block pouring; surface protection, etc.
Hope it helps!
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