Specific Latent Heat of Vaporization vs Evaporation

[Peter G.]

Hi,

When studying and thinking about the concept of Specific Latent Heat of Vaporization I keep falling in the trap of confusing it with evaporation - in the end, in both cases water in the liquid state is being changed into vapor.

Could anyone help me differentiate the two ideas?

Thanks,
Peter G.

 

[rock.freak667]

Evaporation is the process by which a liquid is converted into a gas.

The specific latent heat is the energy per unit mass needed to convert something from a liquid to a gas.

 

[Peter G.]

Oh, ok. But we can only calculate the Specific Latent Heat of Vaporization when the temperature is the boiling point right? Or is it because the value we are usually given is the energy required for when the temperature, in the case of water, is 100 degrees Celsius?

 

[rock.freak667]

Oh, ok. But we can only calculate the Specific Latent Heat of Vaporization when the temperature is the boiling point right? Or is it because the value we are usually given is the energy required for when the temperature, in the case of water, is 100 degrees Celsius?

Well boiling and evaporation are both types of vaporization. Boiling just happens at one temperature and evaporation happens below that temperature.

Usually the specific latent heat of vaporization values you are given are measured at the boiling point.

So if you want to know the latent heat at some other temperature then you'd need to get the corresponding value.