These sub-groups include hydrocarbons, alcohols, and organic acids. Hydrocarbons are organic compounds that contain only hydrogen and carbon atoms. Many hydrocarbons are used as fuel for stoves, outdoor grills, and even heaters in hot-air balloons.Examples of hydrocarbons include the compounds, methane (CH4), propane (C3H8) , butane (C4H10), and ethane (C2H6).he most obvious similarity is that they all contain the amazing element - carbon. Most also contain hydrogen and oxygen as well. It is important to note that while all organic compounds contain carbon, not all carbon compounds are organic.