Flammable LiquidsBy Tuvia Reback

So how can liquids be flammable?

As young kids, we all learned that liquids are used to put out fires. So how is it possible that certain liquids can actually be set on fire?

Hydrocarbons

The reason that chemicals like gasoline and ethanol are so flammable, is because they are types of hydrocarbons. Hydrocarbons are chemical compounds that consist entirely of carbon and hydrogen, and range from simple molecules such as methane, to polymers such as polystyrene that are made up of thousands atoms.

So why are hydrocarbons flammable?

To understand why hydrocarbons are flammable we need to really understand combustion.

Combustion is when there is a release of energy responding to a reaction between a fuel and an oxidant.

Lets use ethanol as an example:

When the carbon and hydrogen of ethanol reacts, it is oxidized and becomes bonded to oxygen. This process releases heat energy (fire) in a combustion reaction:

CH3CHOH + O2 ==> H2O + CO2 (ethanol) + (oxygen) ==> (water) + (carbon dioxide)