
%0 Journal Article
%A Fenby, DV 
%A Chand, A 
%T Enthalpy of the isotopic exchange reaction H<sub>2</sub>O + D<sub>2</sub>O &#8594; 2HDO
%J Australian Journal of Chemistry
%D 1978/02/01
%V 31
%N 2
%P 241-245
%K 
%R https://doi.org/10.1071/CH9780241
%U https://www.publish.csiro.au/paper/CH9780241 
%X The enthalpy of the reaction                           H2O(l)+D2O() &#8594; 2HDO(l)  at 298 K is calculated from the statistical-mechanical enthalpy of the corresponding gas-phase reaction and recent vapour-pressure isotope effect results. Enthalpies of the same reaction obtained from calorimetric results by assuming that the H2O + HDO + D2O liquid mixture is an ideal solution agree, to within the estimated uncertainities, with the calculated value. It is concluded that any 'physical' contributions are less than 20% of the measured enthalpy changes. Molar excess enthalpies of D2O(l)+H2O(l) at 298.15 K are reported and compared with earlier studies. Enthalpies of reaction obtained from our excess enthalpies show a systematic variation with mole fraction. 
