The alkanes The series of compounds which have the general empirical formula CnH2n+2, where n is an integer, is called the alkane, or paraffin The lighter members of the alkane series are gases, the members of intermediate weight are liquids, and the heavier members are solids. From the formulas of the compounds it is evident that each member differs from the preceding one by the increment CH2. A series of compounds in which each member differs from the one before it by a common increment is called a homologous seriesThe alkanes ◼ The series of compounds which have the general empirical formula CnH2n+2, where n is an integer, is called the alkane, or paraffin. ◼ The lighter members of the alkane series are gases, the members of intermediate weight are liquids, and the heavier members are solids. From the formulas of the compounds it is evident that each member differs from the preceding one by the increment CH2 . A series of compounds in which each member differs from the one before it by a common increment is called a homologous series