The carbon reactants for a combustion reaction are any carbon-containing compounds that can be oxidized by the reaction with oxygen. Here are some common examples:

* Fossil fuels:

* Hydrocarbons: These are the most common fuel source. Examples include methane (CH4), propane (C3H8), butane (C4H10), gasoline (a mixture of hydrocarbons), diesel fuel, and kerosene.

* Coal: A solid fuel primarily composed of carbon.

* Biofuels:

* Wood: Primarily composed of cellulose, a complex carbohydrate made of carbon, hydrogen, and oxygen.

* Ethanol: A biofuel produced from plants.

* Biodiesel: A biofuel produced from vegetable oils or animal fats.

* Other carbon-containing compounds:

* Carbon monoxide (CO): A flammable gas that can be used as fuel.

* Carbon black: A finely divided form of carbon used as a pigment.

The key point is that these reactants all contain carbon atoms that can combine with oxygen to form carbon dioxide (CO2) during the combustion process.