The Challenge: Make Ice |
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What liquids could we use as a coolant?
There are a number of possibilities but it depends on two key properties: boiling point and
latent heat of vaporization.
The latent heat of vaporization of a liquid is the amount of energy in joules required to
turn one gram of the liquid into a vapor. When you get out of the shower
or bath and feel cold it is because for every gram (.03 oz.) of water that evaporates
from your skin 2264 joules (539 calories) of energy are being used to
evaporate that gram of water. The energy is taken in the form of heat
from you and therefore you feel cold.
Boiling temperature
and latent heat of vaporization of some liquids:
| Liquid at atmospheric
pressure |
Boiling Temperature
oC (oF) |
Approximate Latent
Heat of Vaporization, (joules/gram) |
| Ether (C2H5)2O |
34.5 (94.1) |
378 ( 90 calories) |
| Acetone (CH3COCH3) |
56.2 (133.16) |
987 (235 calories) |
| Methanol (CH3OH) |
64.5 (148.1) |
1008 (240 calories) |
| Ethanol (C2H5OH) |
78.3 (172.94) |
848 (202 calories) |
| Water (H2O) |
100 (212) |
2264 (539 calories) |
Finding the best coolant liquid 
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