The microdynamic mechanism of the phenomenon, which the static permittivity of sodium chloride aqueous solution with concentration of mol/L holds constant with the change of temperature, is clarified. The equilibrium compensation between the decrement of the permittivity part due to the water molecular polarization and the increase of that originated from the ionic polarization as increasing temperature is responsible for this phenomenon. The dipole moment reduction of water molecules as rising temperature is also confirmed by the model. |