How is heavy water prepared? Compare its physical properties with those of ordinary water.

Property

H₂O

D₂O

Molecular mass (g mol-1)     

18.015

20.0276

Melting point/K         

273.0  

276.8

Boiling point/K          

373.0  

374.4

Enthalpy of formation/kJ mol-

-285.9 

-294.6

Enthalpy of Vaporisation (373 K)/kJ mol^-1

40.66  

41.61

Enthalpy of fusion/kJ mol-1

6.01    

—

Temp of max. density/K        

276.98

284.2

Density (298 K)/g cm-3         

1.0000

1.1059

Viscosity/centipoise  

0.8903

1.107

Dielectric constant/C2/N.m2 

78.39  

78.06