Is oil a hydrocarbon

Answer 1

No, silicones are synthetic compounds where the element silicon replaces the element carbon. They can be anything from silicone oils to silicone plastic polymers (even silicohydrates equivalent to carbohydrates could be made). They are more stable and tolerate higher temperatures without breaking down or decomposing than the equivalent carbon based compound would. True silicones contain no carbon atoms in their molecules.

The simplest silicone is silane (SiH4) a gas, corresponding to the carbon based methane (CH4) gas. Unfortunately the silicone silicon dioxide (SiO2) is a solid, corresponding to the carbon based carbon dioxide (CO2) which is a gas, which makes silicone based lifeforms very unlikely.

Do not confuse silicone (a class of compounds) with silicon (an element)!

Answer 2

Oil that comes out of the earth contains a mixture of various hydrocarbons and a few other chemicals. It does not contain just one hydrocarbon. Refineries process the petroleum and separate out various products, natural gas, gasoline, diesel fuel, asphalt, and other items.