Cooling Things with Ice Water Bath

[justadream]

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Let's say you have a hot object.

Why does it cool faster if you have it in an cool water (let's say at 1 degree C) than it does if you let it sit in a refrigerator (also at 1 degree C)?

 

[Cawolf]

Water conducts the heat away more effectively than air.

 

[justadream]

@Cawolf

But why?

Is is something to do with heat capacity?

 

[Cawolf]

It is actually a property of the substance called thermal conductivity.

It describes how much power a substance can absorb at a certain distance and temperature.

The heat exchange of two substances is calculated using Fourier's Law.

Water is more than twice as conductive as air.

 

[justadream]

@Cawolf

So apart from being given values for thermal conductivity, can you tell me what factors would provide something with greater thermal conductivity?

For example, if I am given Random_Liquid_1 and Random_Liquid_2, can I look at structure/polarity/molecular_weight?

 

[Cawolf]

As far as that goes, I am not sure - I bet it has something to do with the bonding.

I always worked with problems where the conductivity was given or needed to be calculated.

Metals are high, gasses are low.

I found a table you could look at at, maybe you can determine that.

http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thrcn.html

 

[justadream]

@Cawolf

"With increasing density,moisture and temperature the thermal conductivity increases too."

http://tpm.fsv.cvut.cz/student/documents/files/BUM1/Chapter16.pdf


Water is pretty moist so I guess it makes sense.