Fuel burns in a car engine - AQA - GCSE Chemistry Combined Science - Question 2 - 2019 - Paper 2

Oxides of nitrogen (NOx) are produced in a car engine primarily due to high temperatures that occur during the combustion process. At these elevated temperatures, nitrogen from the air reacts with oxygen, forming nitrogen oxides. The conditions within the engine allow for these two elements—oxygen and nitrogen—to bond and react, contributing to the formation of NOx emissions.