The boiling point of water is 100℃, which is not natural but artificial. People define the temperature of water when it just freezes at standard atmospheric pressure as 0℃; The boiling temperature is defined as 100℃, and then the temperature difference between them is divided into 100 parts, each part is 1℃, and the boiling point of water is 100℃.
Boiling point refers to the temperature at which a liquid boils. Boiling is a violent vaporization phenomenon that occurs simultaneously inside and on the surface of liquid at a certain temperature. The boiling point is the temperature at which the liquid boils, that is, the saturated vapor pressure of the liquid is equal to the temperature at which the external pressure is applied. Different liquids have different boiling points. The boiling point changes with the change of external pressure, and the pressure is low, so is the boiling point.
Influencing factors of boiling point of water
1, boiling point is related to air pressure; The boiling point of liquid increases with the increase of surface air pressure and decreases with the decrease of air pressure. When the air pressure decreases, the boiling point of water will be lower than 100℃.
Because the action of atmospheric pressure on water will prevent the evaporation of water molecules, once the atmospheric pressure rises, it means that water vapor needs to have a higher temperature. Similarly, when the air pressure decreases, just as there is less protective armor on the water surface, water can evaporate and boil at a lower temperature.
2. The boiling point is related to the terrain; The higher the altitude, the lower the boiling point of water. This is because the atmospheric pressure decreases with the elevation of the terrain, and the boiling point of water gradually decreases with the elevation. Generally, the boiling point of water is 97℃ at an altitude of 1000m, 91c at an altitude of 3000m and 72℃ at Mount Everest at an altitude of 8848km.
The boiling point of water on the plateau is less than 100℃, so it is difficult to cook quickly. Therefore, it is best to cook in a pressure cooker on the plateau. Pressure cooker can increase the air pressure in the pot, raise the boiling point of water, and also raise the temperature of cooking food, saving both fuel and time.
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