Write a note on heavy water.

Explanation

`to` Deuterium oxide `(D_(2)O)` is known as heavy water.
`to` Preparation : Heavy water is obtained by the exhaustive electrolysis of water.
`to` The physical properties like molecular mass, melting point, Boiling point etc., of `D_(2)O` are heavier than water. But di electric constant and solubility are low for heavy water when compared to water.
`to` Chemical properties :
a) Heavy water reacts with calcium carbide and forms Deuteroacetylene.
`CaC_(2)+2D_(2)OtoC_(2)D_(2)+Ca(OD)_(2)`
b) Heavy water reacts with sulphur trioxide and forms Deutero sulphuric acid.
`SO_(3)+D_(2)OtoD_(2)SO_(4)`
c) Heavy water reacts with Aluminium carbide and forms Deutero methane.
`Al_(4)C_(3)+12D_(2)Oto3CD_(4)+4Al(OD)_(3)`
Uses :
`to` It is used as a moderator in nuclear reactors to decrease the speed of neutrons.
`to` It is used to study the reaction mechanism in exchange reactions.
`to` It is used for the preparation of deuterium and deuterium compounds.