How does pressure affect the boiling any melting/freezing point of a substance ?
How does pressure affect the boiling any melting/freezing point of a substance ?
The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the outer (atmospheric) pressure. If the outer pressure is high (for example at the Dead sea, or in a pressure cooker, you have to raise the vapor pressure by heating, hence raising the temperature, bringing water to boil at a temperature higher than 100 °C. Water (as an example) boils at 100 °C at the sea level, but can boil at 80 °C, 50 °C, 20 °C or less according to the pressure on the liquid. Water boils at 71 °C at the top of Mount Everest.
The same is with the melting point, the temperature at which solid and liquid are at equilibrium, and which depends on the pressure on the system. you can melt ice which has a temperature of -10 °C simply by putting high pressure on it.
The boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the outer (atmospheric) pressure. If the outer pressure is high (for example at the Dead sea, or in a pressure cooker, you have to raise the vapor pressure by heating, hence raising the temperature, bringing water to boil at a temperature higher than 100 °C. Water (as an example) boils at 100 °C at the sea level, but can boil at 80 °C, 50 °C, 20 °C or less according to the pressure on the liquid. Water boils at 71 °C at the top of Mount Everest.
The same is with the melting point, the temperature at which solid and liquid are at equilibrium, and which depends on the pressure on the system. you can melt ice which has a temperature of -10 °C simply by putting high pressure on it.
