Is the internal energy of 1kg of water at the same temperature equal to that of 1g of water? Why

To answer this question, one must first understand what is internal energy: the sum of the kinetic and potential energy of all the molecules inside an object is called the internal energy of an object.

The kinetic energy of a molecule has the following properties

Temperature is a sign of the magnitude of the average kinetic energy of a molecule, the higher the temperature, the greater the average kinetic energy of the molecule;

Objects of different substances, if the temperature is the same, the average kinetic energy of their molecules is the same;

The average kinetic energy of a molecule is independent of the magnitude of the velocity of the macroscopic object.

The kinetic energy of the molecule is the potential energy:

Its size depends on the volume and state of the object. There is both gravitational and repulsive force between molecules, and when the distance between molecules is less than the equilibrium distance of gravitational force and repulsion, as the distance between molecules decreases, the molecular potential energy.

Enlarge; When the distance between molecules is greater than the equilibrium distance, the potential energy of the molecules also increases with the increase of the distance between molecules.

When the distance between the molecules is equal to the equilibrium distance, the potential energy of the molecule is minimal.

Therefore, it cannot be simply understood that the molecular potential energy is directly proportional to the volume of the object.

or inversely proportional relationships.

At the same time, it should be noted that the total number of molecules inside the object, n, n depends on the mass of the object. changes in the state of matter.

In the process, such as the melting process, in general, the molecule changes from a more stable state to a more unstable state, so the potential energy of the interaction between the molecules increases.

It can be seen that the internal energy of an object is determined by four factors: mass, temperature, volume and state of matter.

Therefore, 1kg of water with the same temperature and 1g of water, because of the different mass, the number of molecules contained in the interior is different, so the internal energy is not the same, even in the case of equal mass, the difference in external pressure will lead to different volumes, resulting in different molecular potential energy, and have no internal energy.

Yes, when they are all absolute zero.

Let the temperature after mixing be tCelsius, according to q suction = q discharge, the equation can be columned, c water * 5kg * (t-20) = c water * 3kg * (80-t), the solution is t = . That is, the temperature after mixing is Celsius.

The degree of heat and coldness measured on one of several arbitrary scales based on an observable phenomenon (e.g., the expansion of a column of mercury). Temperature is a manifestation of the translational kinetic energy between molecules within an object.

The faster the molecule moves, i.e., the higher the temperature, the hotter the object; The slower the movement of the molecules, i.e., the lower the temperature, the colder the object. From the point of view of molecular motion theory, temperature is the sign of the average kinetic energy of the molecular motion of an object, and temperature is the thermal motion of the molecule.

of collective performance, which is statistically significant.

For vacuum, the temperature is expressed as the ambient temperature, which is a manifestation of the average kinetic energy between the molecules in the object in the vacuum environment. The temperature of the object is different in different vacuums under the radiation of different heat sources, and this phenomenon is the vacuum ambient temperature.

For example, an object is hotter in space closer to the Sun; The object is in space farther from the sun, and conversely, the temperature is lower. This is solar radiation.

Effect on the ambient temperature of space.

Atmosphere. The temperature of the medium gas is air temperature, which is meteorology.

Common nouns. It is directly affected by the sunshine of Congtan: the more sunlight, the higher the temperature. China on the Celsius scale.

Denote. The surface air temperature referred to by the meteorological department refers to the temperature in the louver box at about the height of the ground.

Solution: Let the temperature after mixing be t degrees Celsius, and according to Q absorption and Q discharge, the equation can be obtained: Pai Su.

C water * 5kg * (t-20) = c water * 3kg * (80-t).

The solution is t=, that is, the temperature after the dust is mixed and the temperature is Celsius.

In this problem, we must first know the law of conservation of energy, that is to say, when two parts of water are mixed together, the internal energy is not changed, and the temperature of water is calculated according to the specific heat capacity The solution of this problem is: according to the law of conservation of energy, q total = q100 + q50 = temperature t = q cm = 840000 (

Let m1 be the quality of the hot water and m2 be the quality of the cold water.

It can be obtained from q=cm town banquet t.

Because the heat released by hot water from 50 to 30 is equal to the heat absorbed by Yuxiang Silver cold water from 20 to 30.

So cm1 t1 = cm2 t2

The solution yields m2 = 6kg

30 degrees.

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In particular, the solar water heater with auxiliary electric heating function is mainly based on solar energy, and the energy utilization mode supplemented by electric energy makes the solar water heater operate normally all year round, and the efficiency is still relatively high when the ambient temperature is low. Its disadvantages are that the volume is relatively large, the glass tube is fragile, the pipe is easy to accumulate scale, and it cannot be operated under pressure.

Classmates and other teachers will shoot the process for you, can you adopt it? Schoolmate.

Let the temperature of the cold water be raised from T 01 to T and the heat absorbed will be Q 1; The temperature of the hot water is reduced from T 02 to T, and the heat deficit of the released plexus is Q2.

After full mixing, regardless of heat loss, Q suction = Q discharge, i.e., laughing calendar CM 1 (T-T 01) = CM2 (T 02 -t).

i.e.: 3 J (kg) 5 kg (t-20) = 3 J (kg) 10 kg (80-t).

The solution touches Zheng Sou: t=60

A: The temperature of warm water is 60

This is the chapter of internal energy in the knowledge of the cautious, this part of the content is relatively single, as long as you remember the formula, or Zen Huai is easier to solve.

The conclusion is that water vapor at the same temperature and mass is greater (not smaller!) than the molecular potential energy of water. ）。

Explanation: To turn water into water vapor, it needs to absorb heat, and heat absorption does not increase its temperature, that is, it does not increase the kinetic energy of the molecule, so it can only increase the potential energy of the molecule, so the molecular potential energy of water vapor is greater than the potential energy of water.

For water of the same mass, the molecular kinetic energy is only determined by the temperature, so if the mass of water and water vapor of the same temperature is the same, the molecular kinetic energy is the same.

In addition, when the biological state changes, from liquid to gas, the molecular spacing becomes larger, and the molecular force needs to be overcome to do work, so the molecular potential energy increases.

Water vapor, or water vapor for short, is the gaseous form of water (H2O). When water reaches its boiling point, it turns into water vapor. At one standard atmosphere at sea level, water has a boiling point of 100°C or 212.

Water can also slowly evaporate into water vapor when it is below the boiling point. In a very low pressure environment (less than atmospheric pressure), ice will directly sublimate into water vapor. Water vapor is a colorless and transparent gas that is invisible to the naked eye, even with a microscope.

When a large amount of water vapor condenses in the air, it often appears as a clump""white gas" is often mistaken for water vapor. If the water vapor turned into boiling water is cooled in the air, it can be seen that the "white gas" is not water vapor, but small water droplets formed by water vapor condensed floating in the air by comparing the visibility, color, shape, and location of occurrence between "white gas" and water vapor. Generally speaking, we call "white gas" "white mist".

I hope I can help you with your doubts.

Let the equilibrium water temperature be x, cm1δt1=cm2δt2, then: c* solution x=25

That is, the water temperature after the balance of the flat and bright Kai state is 25