From: argonster@hotmail.com   
      
   iain-3@truecircuits.com wrote:   
   > The JANAF heat of formation for C is 711.2 kJ/mol.  That's a lot.   
   >   
   > If I do the simple heat of formation at 0 K equation for a   
   > hydrogen-oxygen rocket, I get:   
   >   
   > H2 + 0.5*O2 -> H20 + 238.9 kJ/mol  (= 13.27 kJ/g)   
   >   
   > If I do the same equation for a carbon monoxide rocket, I get:   
   >   
   > C + 0.5*O2 -> CO + 825.0 kJ/mol    (= 29.45 kJ/g)   
   >   
   > That's a lot better!   
   >   
   > I haven't heard of this before, so I'm probably screwing up.   
   > Can anyone suggest where I'm screwing up?   
   >   
   First of all I think you're using the formation enthalpy of gaseous   
   Carbon. Solid carbon (graphite) has a formation enthalpy of 0.   
   Diamonds (crystaline carbon) are unstable, and will actually release a   
   little more energy compared to graphite when you oxidize them.   
      
   Next, carbon burns normally into CO2, but that will release more energy   
   than CO, so that's just better.   
   (CO is an incomplete combustion. Also it's very toxic and will cause   
   oxygen deprivation if inhaled.)   
      
   regards,   
   Christian   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)