How does atmospheric pressure affect the boiling point of water?

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.

Because in the process of liquid boiling, the volume is changed from the liquid phase to the gas phase, and its volume is larger, taking water as an example: the volume of the liquid phase is converted to the gas phase at 1 standard atmosphere, and its volume increases by more than 1300 times.

Secondly, when the liquid is boiling, the vapor inside the liquid (that is, the bubble that emerges), when the vapor pressure (saturated vapor pressure) is equal to the outside air 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 increased to make the vapor pressure increase to 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.

It is like this, the boiling point of water is essentially the temperature of the transition from liquid to gaseous state of water, and the fundamental reason for this qualitative change is that water molecules gain enough energy, because the energy obtained can be achieved by work and heat transfer, so the more heat the water receives under a certain pressure, the more energy it contains, and when the energy is higher than a certain value, the substantial transformation of water from liquid to gaseous state is realized.

At the same time, it should be noted that the effect of pressure on water can actually be understood as doing work, and the volume of the pressure will decrease slightly, and the density of water molecules will increase, so the energy obtained by water molecules will also increase. Therefore, the heat energy required to complete the energy above a certain value is not so much, so it can boil without a temperature of 100 degrees, so its boiling point is lower than 100 degrees.

Therefore, when the pressure increases, the boiling point of the water decreases, and when the pressure decreases, the boiling point of the water increases.

As the pressure increases, the boiling point of water increases, and when the pressure decreases, the boiling point of water decreases.

The relationship between the boiling point of water and atmospheric pressure: when the air pressure is greater, the boiling point will also be higher; When the air pressure is lower, the boiling point is also lower, so at standard atmospheric pressure, the boiling point of water is 100 degrees. The boiling point is different in different places, because the air pressure is different in different places, so the boiling point is also changed.

Water boiling can be regarded as a large-scale vaporization phenomenon, that is, when water molecules are heated, the energy dynamics between the molecules increase. When a liquid boils, the water bubbles produced inside it are equal to the pressure applied by the outside world, and the bubbles will continue to rise, making a boiling sound. However, how much boiling water can escape from the surface of the water is not only related to the boiling point of the water, but also related to the atmospheric pressure outside.

When the atmospheric pressure is strong, less water escapes, and the less likely it is to form a boil. Conversely, when the atmospheric pressure is low, a little more water escapes.

The relationship between the boiling point of water and atmospheric pressure is that with the increase of atmospheric pressure, the boiling point of the same liquid also increases, and vice versa, it decreases Usually the boiling point of water is 100 which means at 1Standard atmospheric pressureThe boiling point of water is different when the air pressure above the water surface is different.

Water has many important functions in the body:1) Water is the protoplasm of the cell.

important components.

2) Water acts as a solvent in the body to dissolve a variety of electrolytes.

3) Water plays a role in transporting nutrients, metabolic wastes and endocrine substances (such as hormones) in the body.

4) Water has high thermal conductivity and specific heat.

It can act as a "heat carrier" to transfer heat between the body and the surface, which helps the body to regulate body temperature.

The boiling point of water increases with the increase of its surface atmospheric pressure and decreases with the decrease of atmospheric pressure. So in the plateau area the boiling point of water does not have 100

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 pressure is *10 mmHg, the boiling point of water is: 81 , .

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 the water exists in the vacuum, it will immediately vaporize, 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 is not non-existent.

The table comparing the boiling point of atmospheric pressure and water is as follows:

The higher the atmospheric pressure, the higher the boiling point of the water, which is related to the saturation pressure of the water. The atmospheric pressure is proportional to the boiling point of water, the greater the atmospheric pressure, the higher the boiling point, the lower the air pressure, the lower the boiling point, the liquid produces the vapor pressure when volatilizing, 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 achieve boiling, and when the external pressure decreases, the temperature is relatively low to make the vapor pressure equal to the external pressure and reach boiling.

At the same atmospheric pressure, the boiling point of the liquid is different for different bodies. 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 saturated air pressure of ether is Pa (44 cm Hg) lower than the atmospheric pressure, and the temperature rises slightly, so that the saturated vapor pressure of the ether is equal to the atmospheric pressure, and the ether can be boiled by heating it to 35.

If the liquid contains impurities, it also has an effect on 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.

Here's how the relationship goes.

The air pressure increases, which increases the boiling point of water.

Why do it? The greater the pressure, the greater the obstruction effect of the source judgment, and the higher the boiling point of water.

The relationship between the boiling point of water and the air pressure.

The boiling point of water is related to atmospheric pressure, because water also changes its boiling point at different atmospheric pressures. As the atmospheric pressure increases, the boiling point of water also increases, and when the atmospheric pressure decreases, the boiling point of water also decreases.