Characteristics of combustion mixtures

Apart from the propergols, the combustion-agent most frequently used for energy 

Fuel Petrol JetAl Diesel fuel Residue 

Dry air contains mainly nitrogen and oxygen, as well as small quantities of rare gases, the main one of which is argon. 

In order to simplify the calculations of the combustion reactions, approximations of the molar fractions can be made by taking into account only N2, O2, and Ar where  

In combustion, specific terms are used to characterize the initial composition of the reaction mixture. The reference taken is the stoichiometric combustion reaction leading to the formation of CO2 and H2O  

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