Deutero methane is obtained by the deuterolysis of :
Heavy water D2O deuterium oxide:
Constant H2O D2O
Molecular mass 18.015 20.028
Maximum density(g cm−3) 1.000 1.106
Melting point(K) 273.2 276.8
Boiling point(K) 373.2 374.4
heat of fusion (kJ mol^{-1}) at 273 K 6.01 −
heat of vapourization (kJ mol^{-1}) at 373 K 40.66 41.61
heat of formation (kJ mol^{-1}) at 273 K −285.9 −294.6
Ionization constant 1.008×10−14 1.95×10−15
Important uses of heavy water:
1. Moderator and coolant in nuclear reactors
2. In the study of mechanism of chemical reactions
3. Starting material for the preparation of a number of deuterium compounds
Hard and soft water:
Water which produces lather with soap solution readily is called soft water.
E.g. Distilled water, rain water and demineralised water
Water which does not produce lather with soap solution readily is called hard water.
E.g. Sea water, river water, well water and tap water