The compounds butane 1-butene and 1-butyne are all classified as hydrocarbons

            The compounds butane 1-butene and 1-butyne are all classified as Aliphatic hydrocarbons.

Explanation:
                   Hydrocarbons are classified mainly into two classes;

                         1)  Aliphatic Hydrocarbons:
                                                                    Which are open chain, acyclic and may be saturated (containing sinle bonds only) like Butane or might be unsaturated (containing double or triple bonds) like 1-Butene and 1-Butyne.

                         2)  Closed Chain Hydrocarbons:
                                                                     These are closed chain and containing minimum ring in its structure. Closed chain hydrocarbons are further classified as Alicyclic (cyclobutane, cyclopropene et.c) and Aromatic (Benzene, Naphthalene e.t.c).