Excuse me, why is the higher the air pressure, the higher the boiling point

Boiling is a violent vaporization phenomenon, and general liquid vaporization refers to the phenomenon that the molecules on the surface of the liquid overcome the intermolecular forces and diffuse large air.

And there are also intermolecular forces between the molecules in the air, so the vaporized liquid molecules have to overcome the intermolecular repulsion in the air.

When the air pressure is higher, that is, the energy of the molecules per unit space is large (or the number of molecules per unit space is large), of course, it becomes more difficult for liquid molecules to enter the air.

So the boiling point is high.

When the vapor pressure is equal to the external pressure, the liquid boils, and the higher the temperature, the higher the vapor pressure.

Yes. The higher the altitude, the thinner and cooler the air, resulting in less air pressure. For every 12 meters of altitude rise below an altitude of several kilometres, the atmospheric pressure decreases by about 1 mm Hg for every 12 metres above sea level.

The concept of boiling point is the temperature at which the partial pressure of the gas produced by the liquid is the same as the ambient pressure when it is heated and evaporated. When the air pressure is low, the boiling point is low, when the air pressure is high, the boiling point is high, and when the air pressure is megapascals, it is the boiling point of the liquid.

Because the boiling point is affected by atmospheric pressure, the specific depends on the upstairs

I even agree with the point of view upstairs, I am also going to take the high school entrance examination, and the teacher said that the important thing in the high school entrance examination is practice, as well as thinking, if I ask the physics teacher with this question, he will definitely say: "Don't drill the horns of the bull and the high school entrance examination will not be examined." ”

Dude, you won't get so deep in the high school entrance examination.

These questions can only increase extracurricular knowledge.

The air pressure is high, and the boiling point is high.

The boiling point of water will change with the change of air pressure, and the boiling point of water will increase as the air pressure increases; When the air pressure decreases, the boiling point of water decreases. The saturated vapor pressure in the bubbles formed inside the liquid as it boils.

The bubble must be equal to the pressure applied to the outside world for the bubble to grow and rise, so the boiling point is the temperature when the saturated vapor pressure of the liquid is equal to the external pressure.

The influencing factors of air pressure:

1. Altitude.

The air pressure decreases as the altitude increases.

2. Distribution of sea and land: Due to the difference in thermal properties between sea and land, the temperature and air pressure between sea and land change with the season. Northern Hemisphere.

In summer, low pressure forms on land and high pressure over the ocean; Winter is the opposite.

3. Air temperature: On the same level, the high temperature is the low air pressure.

On the contrary, the air pressure is high when the temperature is low.

4. Vertical movement of air: the air pressure at the updraft is often slightly lower than that of the same horizontal macro wheel surface; The opposite is true at the downdraft.

1. The boiling point of water is directly proportional to the atmospheric pressure, that is, when the air pressure increases, the boiling point of water also increases, and when the air pressure decreases, the boiling point of water decreases.

2. For pure water, for every 300 meters of altitude, the boiling point temperature will drop by about 1.

Two sets of data: (1) The relationship between the boiling point of water and the pressure: the boiling point of water is 100 when the pressure is 760 mmHg.

When the pressures are *10 mmHg, the boiling points of water are .

2) The relationship between the boiling point and altitude of water: The boiling point of water is 100 when the altitude is 0.

The altitude is -600m, -300m, 3000m, 6000m, 8848m, and the boiling point of water is .

3. In fact, under vacuum, there is no pressure, so as long as water exists in a vacuum, it will immediately resist positive vaporization, theoretically speaking, there is no liquid in the vacuum.

But in real life, there is no such thing as a complete vacuum, so in a vacuum, water vaporizes very quickly, but it does not exist.

The higher the air pressure, the higher the boiling point.

The boiling point is directly proportional to the air pressure, and the higher the air pressure, the higher the boiling point. The lower the air pressure, the lower the boiling point. When the vapor pressure (saturated vapor pressure) is equal to the external pressure, the liquid will boil, and the temperature and hunger at this time is the boiling point of the liquid.

The boiling point of water is 100 under standard atmospheric pressure, the lower the atmospheric pressure, the lower the boiling point, and the higher the atmospheric pressure, the higher the boiling point. The boiling point is directly proportional to the air pressure. The higher the air pressure, the higher the boiling point.

The lower the air pressure, the lower the boiling point. Boiling is a phenomenon of violent vaporization that occurs simultaneously inside and on the surface of a liquid at a certain temperature.

Introduction to barometric pressure

Barometric pressure is the atmospheric pressure acting on a unit area, i.e., the gravitational force exerted on a vertical column of air that extends up to the upper boundary of the atmosphere per unit area. The famous Magdeburg hemispheric experiment proves its existence. Air pressure is the result of the combined action of the molecular motion of the air and the earth's gravitational field.

Barometric pressure is short for atmospheric pressure, which is the atmospheric pressure acting on a unit area, that is, equal to the weight of the vertical column of air that extends upward to the upper boundary of the atmosphere per unit area. The magnitude of the air pressure is related to conditions such as altitude, temperature, etc. Generally, it decreases with increasing height.

In the horizontal direction, the difference in atmospheric pressure causes the flow of air.

The above content is referenced from Encyclopedia - Barometric Pressure.

The higher the air pressure, the higher the boiling point. Barometric pressure refers to the atmospheric pressure acting on a unit area, and in the international unit it is Pascal, abbreviated as Pa, and the symbol is Pa. It varies not only with altitude, but also with temperature.

The regional difference of air pressure is one of the direct causes of meteorological changes, and it is also an important variable in weather forecasting.

Notes:The central area of high pressure is not conducive to the formation of clouds and rain, and it is often sunny. However, the low pressure causes the air in the area to rise, and the rising air expands due to the decrease in pressure, the temperature decreases, and the water vapor in the air condenses, so the center of the depression often has rainy days.

When the vapor pressure of the liquid rises to atmospheric pressure, the liquid boils, and the temperature at this time is the boiling point of the liquid. On the surface of the substance, the area is s then the atmospheric pressure is p, and it will be subject to the pressure of f = ps is the pressure, so when the area is constant, the higher the boiling point of the substance at the place where the air pressure is larger, on the contrary, when it is at the plateau, the air pressure is very low, so the boiling point is low.

Yes, the higher the air pressure, the higher the boiling point.

The boiling point is directly proportional to the air pressure, the greater the air pressure, the higher the boiling point; The lower the air pressure, the lower the boiling point. Reason: When the liquid volatilizes it produces vapor pressure, when the vapor pressure (saturated vapor pressure) is equal to the external pressure, the liquid will boil, and the temperature at this time is the boiling point of the liquid.

When the external pressure increases, the temperature must be raised to increase the vapor pressure to be equal to the external pressure and reach boiling. When the external pressure is reduced, the vapor pressure can be equal to the external pressure when the temperature is relatively low, and the boiling can be achieved. For the same kind of crystal, the melting point is related to the pressure, and the melting point of the substance at a pressure of 1 atmosphere is generally taken as the normal melting point.

At a certain pressure, both the melting point and the freezing point of the crystalline substance are the same. The melting point of a substance that expands in volume during melting increases when the pressure increases. The boiling point is the temperature at which the boiling of a liquid occurs.

When the liquid boils, the saturated vapor pressure in the bubble formed inside it must be equal to the pressure exerted by the outside world, so that the bubble can grow and rise, so the boiling point is the temperature at which the saturated vapor pressure of the liquid is equal to the external pressure.

Boiling point of different liquids:

At the same atmospheric pressure, the boiling point of different kinds of liquids is also different. This is because the saturation vapor pressure is related to the type of liquid. At a certain temperature, the saturated vapor pressure of various liquids is also constant.

For example, at 20, the saturation pressure of ether is Pa (local elimination of 44 cm Hg) lower than the atmospheric pressure, and the temperature rises slightly, so that the saturated vapor pressure of ether is equal to the atmospheric pressure, and the ether can be boiled when heated to 35.

If there are impurities in the liquid, it will also affect the boiling point of the liquid. The boiling point of a liquid containing solute is higher than that of a pure liquid, which is due to the fact that the gravitational force between the liquid molecules increases after the presence of a solute, the liquid is not easy to vaporize, and the saturated vapor pressure is also smaller.

To make the saturation vapor pressure the same as the atmospheric pressure, the boiling point must be raised. Different liquids have different boiling points under the same external pressure. The relationship between boiling point and pressure can be obtained from the Clausius equation.

The above content reference: Encyclopedia - boiling point.

Yes, the higher the air pressure, the higher the boiling point.

The higher the air pressure, the higher the boiling point. The so-called boiling point is actually the temperature at which the saturation vapor pressure of the liquid stool body is equal to the outside atmospheric pressure. The greater the outside atmospheric pressure, the greater the saturated vapor pressure of the liquid boiling, and increasing the saturated vapor pressure is achieved by increasing the temperature of the liquid, so the higher the air pressure, the greater the boiling point.

Boiling is a phenomenon of violent vaporization difference between the inside and the surface of the liquid at a certain temperature. The boiling point is the temperature at which the liquid boils, that is, the temperature at which the saturated vapor pressure of the liquid is equal to the external pressure. The higher the concentration of the liquid, the higher the boiling point.

The boiling point of different liquids is different. The boiling point changes with the change of external pressure, and the low pressure is also the low boiling point.

The basic properties of boiling point

When the liquid boils, the saturated vapor pressure in the bubble formed inside it must be equal to the pressure exerted by the outside before the bubble can grow and rise, so the boiling point is the temperature when the saturated vapor pressure of the liquid is equal to the external pressure. The boiling point of a liquid is related to the external pressure. When the pressure of the liquid increases, its boiling point increases; When the pressure decreases; The boiling point decreases.

For example, the steam pressure in a steam boiler is about a few tens of atmospheres, and the boiling point of water in a boiler can be more than 200. For another example, when cooking rice in a high mountain, the water is easy to boil, but the rice is not easy to cook. This is due to the fact that the atmospheric pressure decreases with the increase in the topography and the boiling point of water also gradually decreases with the increase in altitude.

At an altitude of 1,900 meters, the atmospheric pressure is about 79,800 Pa (600 mm Hg), and the boiling point of water is that those with a low boiling point generally vaporize first, while those with a high boiling point are generally more difficult to vaporize.

The above content reference: Encyclopedia - boiling point.

Encyclopedia - Barometric pressure.