Wednesday, September 22, 2010

latent heat of vaporization

A non-geology topic for a second.

We have been canning peaches this past week and as I was waiting and waiting for the canner water to start boiling I was thinking of a quick blog post. Canning is the culinary analog for splitting firewood. Lots of work in the fall leads to fresh peaches in February. All together we have about 40 jars of peaches. That sounds like a jar a week until next summer!

yes it was night by the time we had put enough energy in the system to change states from liquid to a gas.
Working the peaches
Filling the jars

Check out how much energy it takes to boil water compared to other materials. At a point in my ancient history, I was an operator in a coal fired power plant. That is when I first learned that much of the coal we burned was to put water over the edge from a liquid to a gas. (chart taken from wikipedia)


SubstanceLatent Heat
Fusion
kJ/kg
Melting
Point
°C
Latent Heat
Vaporization
kJ/kg
Boiling
Point
°C
Alcohol, ethyl108−11485578.3
Ammonia339−751369−33.34
Carbon dioxide184−78574−57
Helium 21−268.93
Hydrogen(2)58−259455−253
Lead[3]24.5327.58711750
Nitrogen25.7−210200−196
Oxygen13.9−219213−183
R134a −101215.9−26.6
Toluene −93351110.6
Turpentine 293
Water33402260 (at 100oC)100


2 comments:

mountainbeltway said...

"That is when I first learned that much of the coal we burned was to put water over the edge from a liquid to a solid."

...I assume you mean "from a liquid to a gas?"

Geology Happens said...

oops another of those "stupid" mistakes I was so good at while an undergrad. Thanks for showing it to me