Preparation of chlorine by electrolytic method : Chlorine is obtained by the electrolysis of brine solutions (Conc. NaCl). `Cl_(2)` gas is liberated at anode.
`2NaCl to2" Na"^(+)+2Cl^(-)`
`2" H"_(2)O+2e^(-) to2OH^(-)+H_(2)` (cathode)
`2" Cl"^(-)to Cl_(2)+2e^(-)` (anode)
i) NaOH :
Chlorine reacts with cold dil. NaOH to form sodium hypochlorite.
`Cl_(2)+2" NaOH"to"NaCl"+"NaOCl"+H_(2)O`
ii) `Cl_(2)` reacts with hot conc. NaOH to form sodium chloride and sodium chlorate.
`3" Cl"_(2)+6" NaOH"to5" NaCl"+"NaClO"_(3)+3" H"_(2)O`
