-----Original Message----- From: Bob Cook >> The textbook energy from burning hydrogen in oxygen is 2.85 eV per molecule of H2O
> Is that energy based on the differential mass of (H2 molecule + O2 molecule) and 2H2O molecules? Well yes, it can be stated that way - although it is a chemical reaction... nevertheless - there is mass-to-energy conversion, just as with a nuclear reaction. Obviously, only a tiny mass is involved so we normally do not state it that way. The URL: http://hyperphysics.phy-astr.gsu.edu/hbase/molecule/boneng.html shows the gain in energy (loss of mass) at 5.7 eV for two molecules. It would be hard to weigh that photon on a scale with any accuracy :)
