[at-l] Chemistry...

[tschamp@tiac.net (The Wizard)]

At 10:09 PM 1/25/01 -0500, James Bullard wrote:

>??? According to the Austin Public Library site the weight of a gallon of 
>gasoline is "1 gallon = 5.50253 - 5.75265 lbs. at 60 ° F". According to my 
>high school science teacher, matter and energy can be interchanged but not 
>created or destroyed. If most of the matter in a 5.7 pound gallon of gas 
>is changed to energy how could you have 20 pounds of carbon dioxide left 
>after burning? Resident chemical engineers, step forward please.

This is easy, and I'm not even a chemical wizard.  Oxygen weighs something, 
you see.  Most fuels are combinations of H and C, so making compounds by 
adding some "O" , by burning the fuel, adds much mass to the total 
byproducts.

(Chemists hardly ever refer to "weight" of compounds, it's "mass"...)

For an even more illustrative example,  take a certain amount of pure 
hydrogen, say a blimpful.  The "weight" of this H is actually negative on 
the earth since it's lighter than air.  Set it aflame and what  do we 
get?  Water, or more likely steam, but quite heavier than the original H by 
itself...

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
The Wizard!  A gleam in his eye, a bounce in his step!