Question: what is the difference in the molecular mass of any two adjacent homologous?
Answer: Adjacent members in a homologous series are called adjacent homologues. ... You can find that the adjacent homologues differ by a unit of CH2 inserted to the chain. So the difference molecular mass between the adjacent homologues will be molecular mass of a CH2 unit, which is 12 + 1 + 1 = 14 atomic mass units.