Vapor pressure or still vapor pressure?
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In chemical engineering, gas and vapor represent two different states. Vaporization or gasification? Vapor pressure or still vapor pressure? Which one is correct or more accurate? Please engage in active discussions!
In my understanding, taking water as an example, when it is heated to the point of boiling, during the phase equilibrium state at the boiling point, it exists as water vapor, corresponding to the saturated vapor pressure; above this temperature it exists as a gas, corresponding to the vapor pressure. I’m not sure if it’s right? :lol
Vapor pressure refers to the pressure exerted by the vapor of a substance present on the surface of a liquid (or solid); this pressure is known as the vapor pressure of that liquid. Water vapor (without three droplets) ； Vapor pressure (with three drops of water)
Steam is the form in which a substance changes from a liquid state to a gas state when heated and subjected to pressure. Steam specifically refers to water vapor, the gaseous form of water. Steam contains vapor, and vapor is a subset of steam. It should refer to vaporization and vapor pressure; if written as vapor pressure, it specifically denotes water vapor pressure. My personal understanding, for discussion
Vaporization is merely a physical process; vaporization involves chemical processes as well
Strictly speaking, there is no such concept as vapor pressure at all; only the concept of vapor pressure exists. Steam is used only when referring specifically to water vapor, but the pressure resulting from the evaporation of liquid components into gas can only be expressed in terms of vapor pressure.
Vapor pressure: Under certain external conditions, liquid molecules in a liquid will evaporate into gas molecules, while gas molecules will also collide with the liquid surface and return to the liquid state. This is a two-phase change that occurs in a single-component system, and equilibrium is reached after a certain period of time. At equilibrium, the concentration of gas molecules reaches its maximum value, and the pressure generated by these gas molecules colliding with the liquid is known as the heat of vaporization. The heat of vaporization is a physical property of a substance. It is defined as: the heat required to evaporate one mole of a substance at a certain temperature under standard atmospheric pressure (101.325 kPa); for a given substance, it is a function of temperature.