The Combustion of Pure Hydrogen by the Reaction $$2 \mathrm { H } _ { 2 } + \mathrm { O } _ { 2 } \rightarrow 2 \mathrm { H } _ { 2 } \mathrm { O }$$

Essay

The combustion of pure hydrogen by the reaction $$2 \mathrm { H } _ { 2 } + \mathrm { O } _ { 2 } \rightarrow 2 \mathrm { H } _ { 2 } \mathrm { O }$$ produces $142 \mathrm { MJ }$ per kg of hydrogen. Compare the energy per kg of octane and the total energy from the individual combustion of its carbon and hydrogen atoms.