Temperature dependence of heat capacity and viscosity of non-associated liquids

The temperature dependence of the viscosity of some non-associated liquids is compared with the variation with temperature of the heat capacity CV at constant volume. Those liquids which show Arrhenius viscosity behaviour throughout the liquid range have no structural contribution to CV. Those liquids which show non-Arrhenius viscosity behaviour at low temperature have a structural CV in the non-Arrhenius region only. Both the non-Arrhenius viscosity and the structural heat capacity arise from the restriction of molecular rotation in liquids.