The structural isomers for C4H10 are butane and methylpropane. They are both colorless odorless gases, but they have different melting and boiling points. Their molecular masses are, however,identical. Industrially butane is used in the blending of fuel while methylpropane is used as a refrigerant.
The longest chain of methylpropane has only 3 carbon atoms, and the fourth carbon atom is connected to the center carbon atom. Butane is not branched. Both butane and methylpropane are alkaline. This means they are saturated hydrocarbons in which the carbon atoms are connected by single covalent bonds. Hydrocarbons make up most of the compounds found in crude oil.