Hey guys...
I'm doing a high-school prac including testing a series of fuels for the energy released during combustion...
We make a bomb calorimeter of some kind, (which means, we light the fuel with a wick and put a beaker of water over the flame and test the temperature change) of course, nothing I made was completely accurate... I know how to explain all that in the discussion though.
The fuels we tested were methanol, ethanol, butan-1-ol, and pentan-1-ol. (The series being the number of carbon atom's in each fuel increases).
I was hoping for help in the sense that, can any of you tell me much about the enthalpy of these fuels in relation to each other? I've got numbers and stuff from wikipedia but I can't really make any sense from the whole thing...
For example:
Methanol has 1 carbon atoms, so the chemical formula is CH3OH but it's density is 0.7918 g cm-3
While Ethanol has 2 carbon atoms, the chemical formula is C2H5OH and it's density 0.789 g cm-3 so it's less than methanol.
Yet butanol and pentanol both have higher density's in the 0.8's ?? Surely if the molecular weight increases the density increases (slightly at least). So why not for Ethanol???
And what does the density and molecular weight have to do with the energy released (or the enthalpy) when tested in the bomb calirometer??? Can someone please help me understand a bit??
Much Appreciated