Air pressure dependent water evaporation

In summary, the evaporation speed of water does not change with varying air pressure, unless the air pressure is lower than the water's vapor pressure, in which case it will boil and significantly increase the evaporation speed. The "Poynting correction" can provide more information on this topic.
  • #1
lesy1
12
0
Imagine a water basin, surrounded by air. How does evaporation speed of water change if the air pressure of surrounding air is 1.000Pa, 10.000Pa, 100.000Pa, 1.000.000Pa, 10.000.000Pa. What is an order of magnite of the evaporation speed change. Where can I read more about that?
Regards.
 
Physics news on Phys.org
  • #2
The surprising answer is that it doesn't change. The evaporation speed is dependent on the partial pressure of the water vapor above it, not the total pressure of the air.

The exception to this is if the air pressure is lower than the water's vapor pressure. Then the water will boil, which significantly increases its evaporation speed (I don't know an exact number though).
 
  • #3
Does there exist any liquid which would change the evaporation speed as a function of air pressure?
 
  • #4
cjl said:
The surprising and incorrect answer is that it doesn't change. (snip)

You are looking for the "Poynting correction."
 
  • #5


I can tell you that air pressure does have an impact on the rate of water evaporation. When the surrounding air pressure is higher, the water molecules on the surface of the water are more tightly packed together, making it more difficult for them to escape into the air. This results in a slower evaporation rate.

As the air pressure decreases, the water molecules have more room to move and escape, leading to a faster evaporation rate. This is why water evaporates faster at higher altitudes where the air pressure is lower.

To give you an idea of the magnitude of the change in evaporation speed, a decrease in air pressure from 10.000.000Pa to 1.000Pa can result in a 10-fold increase in evaporation rate.

If you would like to read more about this topic, I would suggest researching the relationship between air pressure and evaporation, as well as the concept of vapor pressure. You can also find more information in textbooks or scientific articles on atmospheric science or physical chemistry.
 

Related to Air pressure dependent water evaporation

1. What is air pressure dependent water evaporation?

Air pressure dependent water evaporation is the process by which water changes from its liquid form into a gas, known as water vapor, due to changes in air pressure. This process is influenced by factors such as temperature, humidity, and air pressure.

2. How does air pressure affect water evaporation?

Air pressure affects water evaporation by determining the rate at which water molecules can escape into the surrounding air. Higher air pressure compresses the air molecules, making it more difficult for water molecules to break free and evaporate. Lower air pressure allows for easier evaporation as the air molecules are more spread out.

3. What are the effects of air pressure on water evaporation?

The effects of air pressure on water evaporation include the rate of evaporation and the amount of water that can be evaporated. Higher air pressure can slow down evaporation, while lower air pressure can lead to faster evaporation rates. Additionally, lower air pressure can result in more water evaporating compared to higher air pressure.

4. How does temperature play a role in air pressure dependent water evaporation?

Temperature plays a significant role in air pressure dependent water evaporation. As temperature increases, air molecules move faster and are more spread out, resulting in lower air pressure. This decrease in air pressure allows for easier evaporation of water molecules. On the other hand, colder temperatures lead to higher air pressure, making it more difficult for water molecules to evaporate.

5. What are some real-world applications of understanding air pressure dependent water evaporation?

Understanding air pressure dependent water evaporation is crucial in many industries and fields such as meteorology, agriculture, and engineering. It can help predict weather patterns and determine the best times for planting crops. In engineering, it is important for designing and maintaining systems such as refrigerators and air conditioners that rely on water evaporation for cooling. Additionally, understanding this process can also aid in water conservation efforts and managing water resources.

Similar threads

Replies
2
Views
92
Replies
1
Views
1K
Replies
4
Views
9K
  • Mechanics
Replies
3
Views
824
  • Mechanics
Replies
9
Views
2K
Replies
1
Views
1K
Replies
4
Views
2K
Replies
10
Views
1K
Replies
27
Views
2K
Back
Top