octane
No, it's not. Octane is C8H18
Yes, it LOOKS like an empirical formula BUT it is NOT a correct one:Either C9H20 or C8H18 are correct (both are saturated alkanes) but not C8H20
Generally speaking, petroleum is a mixture of compounds known as hydrocarbons. These compounds contain carbon and hydrogen in the ratio of CnH2n+2 for alkanes, the most well-advertised probably being octane (C8H20). In terms of length, one can distinguish between the liquid portion (that which we call oil) with between 5 and 42 carbons, and the gaseous portion (that which we call natural gas) like LPG (liquefied petroleum gas). Now, I'm not so certain about what you meant about your second question, but I'm supposing that you're talking about biogas. Biogas is an alternative energy source employed mostly on the rural (correct me if I'm wrong) level. This utilizes the fact that as organic matter decomposes in the absence of oxygen, a various mix of vapors are produced with methane being the top component. Methane, being an odorless and flammable gas, can then be piped to individuals for use.