https://www.sciencedirect.com/science/article/abs/pii/0002157177900073

Dr Jurgen Weippert thank you for your contribution to the discussion

In a dynamic equilibrium, the rate of evaporation is equal to the rate of condensation. This means that molecules are constantly transitioning between the liquid and vapor phases, but there is no net change in the amount of substance in each phase over time.

At a constant temperature, the vapor pressure of a liquid reaches a point where it becomes equal to the atmospheric pressure. This specific temperature is known as the **boiling point** of the liquid. At the boiling point, the vapor pressure of the liquid equals the pressure exerted on the liquid's surface by the surrounding atmosphere, causing the liquid to transition into vapor throughout its volume.

It's important to note that the boiling point of a liquid varies depending on the atmospheric pressure. For example, water boils at 100 degrees Celsius (212 degrees Fahrenheit) at standard atmospheric pressure, but at lower pressures (e.g., higher altitudes), the boiling point will be lower because the vapor pressure needed to reach equilibrium with the lower atmospheric pressure is achieved at a lower temperature.

To summarize:

- In a dynamic equilibrium at a constant temperature, the rate of evaporation is equal to the rate of condensation.

- The temperature at which the vapor pressure of a liquid is equal to the atmospheric pressure is called the boiling point. This temperature varies based on the surrounding atmospheric pressure.

Dr Pranjit Sarkar thank you for your contribution to the discussion

The system reaches the point where the rate of evaporation is equal to the rate of condensation. This is considered a dynamic equilibrium between the liquid and vapor phase. In a closed system, a dynamic equilibrium will be reached, where the rate of evaporation equals the rate of condensation. It is equilibrium because the number of water vapor molecules above the liquid surface (as measured by the vapor pressure) is no longer changing. Dynamic equilibrium occurs when, for a reversible reaction, the rate of the forward reaction equals the rate of the reverse reaction. Since the two rates are equal, it looks like nothing is happening, but in reality the reaction is continuously occurring at its stable rate. Dynamic equilibrium occurs when, for a reversible reaction, the rate of the forward reaction equals the rate of the reverse reaction. Since the two rates are equal, it looks like nothing is happening, but in reality the reaction is continuously occurring at its stable rate. If evaporation takes place in an enclosed area, the escaping molecules accumulate as a vapor above the liquid. Many of the molecules return to the liquid, with returning molecules becoming more frequent as the density and pressure of the vapor increases. So, as the number of water vapor molecules increases in the air above the water, the condensation rate increases, too. The condensation rate will continue to increase until it matches the evaporation rate, which is a state called equilibrium, meaning the condensation rate equals the evaporation rate. When the rate of evaporation equals the rate of condensation, the dew point is reached, and no more water vapor can be held in the air. This means that there will be no cloud formation, and any excess water vapor will condense into liquid. If the condensation rate exceeds the evaporation rate, the cloud grows and develops. Conversely, if evaporation exceeds condensation, the cloud dissipates. Humidity, or water vapor content of the air, also has an effect on evaporation. The lower the relative humidity, the drier the air, and the higher the evaporation rate. The more humid the air, the closer the air is to saturation, and less evaporation can occur. The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. Vapour pressure is the pressure of the vapour at equilibrium state when the rate of evaporation becomes equal to the rate of condensation. The equilibrium constant does not change at a particular temperature and therefore the vapour pressure remains constant.