What is the empirical formula for hydrocarbon?
Hydrocarbon does not describe a single compound. The term hydrocarbon denotes a chemical that is composed entirely of hydrogen and carbon. Some examples are methane, propane, and butane. They are usually readily combustible and are used as fuel. Since they only contain hydrogen and carbon, the chemicals of all hydrocarbons are base on CH with different subscripts on both elements. If you are only talking about chemicals with carbon carbon single bonds, then the generic empirical formula is C(n)H(2n+2), meaning that for the total number of carbons in the chemical (n), there will be twice that number plus two hydrogens (2n+2).
Adding to the answer by "ncchemist," empirical formula is the simplest, reduced annotation of the ratio of atoms, which in this case is hydrogen and carbon. Empirical formula may not necessarily describe a specific compound because the ratio of the atoms in that compound may be the same with the ratio of atoms in another compound (although I am having a hard time finding this characteristic in just hydrocarbons). But an example of an empirical formula for C6H14 is C3H7.