Melting point, enthalpy of vaporisation and viscosity data of H2O and D2O is given below

 

   H2O

  D2O

Melting point / K

   373.0

   374.4

Enthalpy of vaporisation at (373K) kJ mol-1

   40.66

   41.61

Viscosity / centipoise

    0.8903

    1.107

Given that,

 

H2O

D2O

Melting point/K

373.0

374.4

Enthalpy of vaporization at (373 K)/kJ mol-1

40.66

41.61

Viscosity/centipoise

0.8903

1.107

From this data, it is concluded that the values of melting point, enthalpy of vaporisation and viscosity depend upon the intermolecular forces of attraction.
Since, their values are higher for D2O as compared to those of H2O, therefore, intermolecular forces of attraction are stronger in D2O than in H2O.