how are pollutants formed when gasoline burns, and why are they not shown in the equation?

Question

the chemical equtaion for burning of fuels suggests that water and carbon dioxide are the only product. Now please answer my question with this details

Answer 1

Compared to the formation of CO2 and H2O, these other products are formed in minute quantities, usually in the part per million level.

1. Reactions represent what happens under controlled conditions (pure single compound gasoline, pure oxygen). The burning of gasoline in a car is far from controlled conditions. The reaction in the car also does not occur to 100% as in the written reaction (formation of CO as a product for example).

2. Another reason is that most of the pollutants form due to impurities in the gasoline. Again, minor reactants are not shown in the equation since it implies pure starting materials. These would include sulfur compounds and other organics.

3. Another reactant not shown for the car reaction is nitrogen. We normally write "+ O2", but in a car it is "+O2 + N2 + all the other air components". This is where the nitrogen oxide pollutants arise.

Bottom line, unless you are studying them specifically, minor reactants and products are not normally shown.

Answer 2

because gasoline may consist of many complicated substances
and also because when it burns , there are many complex reactions that we don't use the equation to show them