What is the process that oil molecules undergo when they react with oxygen?

The process that oil molecules undergo when they react with oxygen is known as oxidation. During oxidation, the chemical bonds between atoms in the oil molecules are broken, and new bonds are formed with oxygen. This reaction typically leads to the formation of various byproducts, including free radicals, peroxides, and other complex compounds, which can impact the stability and quality of the oil.

Oxidation is a critical consideration in the use of lubricants and fuels because it can cause changes in viscosity, increase acidity, and contribute to the formation of sludge and deposits, ultimately affecting the performance of engines and machinery. Understanding oxidation helps in determining the proper storage conditions and handling procedures to extend the life of oil products.