[cyberax]

N2O formation enthalpy is just 82kJ/mol. For comparison, water is 240kJ/mol.

It doesn't sound so bad, but when translated into grams, it's 1.86kJ/g for N2O and 13.3kJ/g for water.

In other words, when burning a gram of hydrogen, you get about 120kJ of energy. When decomposing a gram of N2O, you barely get 2kJ.

[saagarjha]

You’re off by a factor of 10 somewhere

[cyberax]

Nope? A gram of water is mostly oxygen. Hydrogen is just 2/18 of the water mass, so that's where the factor of 9 comes from.