The boiling point temperature of water is directly proportional to atmospheric pressure, that is, the boiling point of water increases with the increase of atmospheric pressure, and the boiling point of water decreases with the decrease of atmospheric pressure. But with the increase of altitude, the atmospheric pressure gradually decreases. According to the calculation, the atmospheric pressure will drop by about 30 g/cm ~ 2 every 300 meters, until the altitude is above 3000 meters, which basically follows this law. So in mountainous areas thousands of meters above sea level, the atmospheric pressure is much lower than the sea level. Because of the low air pressure in mountainous areas, the boiling temperature of water there is also low. It is measured that for pure water, the boiling point temperature will drop by about 65438 0℃ every 300 meters. Therefore, boiling water on high mountains usually boils below 100℃.

Two sets of data:

(1) Relationship between boiling point and pressure of water;

When the pressure is 760/mmHg (i.e. 1 atm), the boiling point of water is 100℃.

When the pressures are 380, 7 10, 780, 760×2, 760×5 and 760× 10/mmHg respectively,

The boiling points of water are: 8 1℃, 98. 1℃, 100.7℃, 120℃, 152℃, 179 respectively.

(2) The relationship between boiling point and height of water:

At altitude 0, the boiling point of water is 100℃.

When the altitude is -600 meters, -300 meters, 3000 meters, 6000 meters, 8848 meters and tens of thousands of meters,

The boiling points of water are 102℃,10/℃, 9 1℃, 80℃, 72℃,118℃ respectively.