Final answer:
Fires resulting from combustible liquids like kerosene, gasoline, oil, and grease are classified as Class B fires. These fires involve flammable liquids or gases, and the involved alkanes release significant heat when combusted.
Step-by-step explanation:
Fires that result from combustible liquids such as kerosene, gasoline, oil, and grease are classified as Class B fires. These are fires that involve flammable or combustible liquids, greases, and gases. Alkanes, which are major components in these types of fuels, undergo a highly exothermic oxidation-reduction reaction in the presence of oxygen, producing carbon dioxide and water and releasing a significant amount of heat energy. Gasoline, kerosene, and diesels, are all liquid mixtures primarily made up of alkanes with different carbon chain lengths and molecular masses, obtained from crude oil through fractional distillation based on their boiling points. These substances are considered excellent fuels due to their high energy release when combusted, but this also makes them highly dangerous and capable of initiating Class B fires.