ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 25, Number 3
JKCSEZ 25(3)
June 20, 1981 

The rates of solvolysis for p-nitrobenzyl chloride have been measured by the electric conductivity method in aqueous ethanol from 0.0 to 0. 5 mole fraction of ethanol under various pressures up to 1200bar at 50 and 60℃. The activation parameters, ΔV0≠, ΔH≠ and ΔS≠ are evaluated from the rate constants. The results indicated that ΔV0≠ exhibits an extremum behaviors near 0.3 mole fraction of ethanol and ΔH≠ and ΔS≠ near 0.1 mole fraction of ethanol. This behaviors are discussed in terms of solvent structure variation and the pressure dependences of ΔV≠, ΔH≠ and ΔS≠ are also discussed individually. The signs of the pressure dependence of ΔH≠ and ΔS≠ are shown to be consistent with those required by the Maxwell relationships for classical thermodynamic systems.