Finding how much heat released by evaporation of water

In summary, the conversation revolved around the question of where the 120W measurement came from, with the person initially not understanding but then realizing they missed a slide. The topic of heat release from the human body was also brought up, with the conclusion being that evaporation does not release heat but rather absorbs it from the body.
  • #1
member 731016
Homework Statement
Please see below
Relevant Equations
Please see below
For this,
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Dose anybody please know where they got the 120W from?

Many thanks!
 
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  • #2
There must be more context to the question.
 
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  • #3
haruspex said:
There must be more context to the question.
Thank you for your reply @haruspex!

I'm very sorry, but somehow, I missed the slide before. I think I understand where they got the 120W from now.

Thank you for your help!
 
  • #4
What releases the heat? The water needs to absorb energy in order to evaporate. Evaporation does not release heat.
 
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  • #5
nasu said:
What releases the heat? The water needs to absorb energy in order to evaporate. Evaporation does not release heat.
Thank you for your reply @nasu!

The question was about the heat released from the human body I recall. So I think the water absorbs the heat from the human.

Many thanks!
 

FAQ: Finding how much heat released by evaporation of water

What is the heat of vaporization for water?

The heat of vaporization for water is the amount of energy required to convert one gram of water from liquid to gas at its boiling point. For water, this value is approximately 2260 joules per gram (J/g) or 540 calories per gram (cal/g).

How do you calculate the heat released during the evaporation of water?

To calculate the heat released during the evaporation of water, you can use the formula: Q = m * Lv, where Q is the heat released, m is the mass of the water in grams, and Lv is the latent heat of vaporization. For water, Lv is 2260 J/g.

Is the heat released during evaporation the same as the heat absorbed during condensation?

Yes, the heat released during evaporation is equal in magnitude but opposite in direction to the heat absorbed during condensation. When water evaporates, it absorbs heat from the surroundings, and when it condenses, it releases the same amount of heat back into the surroundings.

Does the temperature of water affect the amount of heat released during evaporation?

The temperature of the water does not directly affect the amount of heat released during evaporation, as the latent heat of vaporization is a constant value. However, the rate of evaporation can be influenced by the temperature, with higher temperatures generally increasing the rate at which water evaporates.

Can the heat released during evaporation be harnessed for practical use?

Yes, the heat released during evaporation can be harnessed for practical applications, such as in cooling systems (e.g., evaporative coolers) and industrial processes. By utilizing the energy exchange that occurs during phase changes, these systems can achieve efficient thermal management.

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