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netheril96
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It's hard for me to find the why,bcz most books only give this without any explanation
Is there anyone who knows the exact reason?
Is there anyone who knows the exact reason?
Fightfish said:Boiling refers to the process whereby a phase change from liquid to gas takes place throughout the liquid. This would imply the formation of gas bubbles beneath the liquid surface. That is why bubbling is a characteristic of boiling liquids.
Now, the pressure in the gas bubbles must be at least equal to that of the surrounding fluid and the atmosphere/environment. Otherwise, the bubbles will collapse, and boiling does not occur. Thus, the boiling can only occur at the point where the vapour pressure (of the gas bubbles) equals the pressure of the surroundings.
Liquid boils because the molecules in the liquid gain enough energy to overcome the intermolecular forces holding them together, causing them to escape into the gas phase.
Saturated vapor pressure is the pressure exerted by the vapor molecules in equilibrium with a liquid at a given temperature. It is the maximum pressure that can exist before the liquid starts to boil.
As the temperature of a liquid increases, the average kinetic energy of the molecules also increases. This results in more molecules having enough energy to escape into the gas phase, leading to an increase in saturated vapor pressure.
The boiling point of a liquid is affected by atmospheric pressure, intermolecular forces, and the nature of the liquid's molecules. Higher atmospheric pressure and stronger intermolecular forces will result in a higher boiling point, while a lower atmospheric pressure and weaker intermolecular forces will result in a lower boiling point.
No, a liquid can only boil at temperatures at or above its boiling point. At lower temperatures, the liquid will not have enough energy to overcome the intermolecular forces and enter the gas phase.