Cl2

• Chlorine was discovered by Scheele


  1774
• Davy established chlorine's elementary nature and suggested the name

  1810
• Chlorine


  Greenish yellow gas with pungent and suffocating odour
• Preparation of chlorine


  1. Heating manganese dioxide with concentrated hydrochloric acid

  2. Action of HCl on potassium permanganate
• Manufacture of chlorine


  1. Deacon's process: Oxidation of hydrogen chloride gas by atmospheric oxygen in the presence of CuCl2 catalyst at 723 K

  2. Electrolytic process: Electrolysis of brine (concentrated NaCl solution)
• Chlorine


  • About 2-5 times heavier than air
  • Can be liquefied easily into greenish yellow liquid which boils at 239 K
  • Soluble in water
• Chlorine reacts with metals and non-metals


  Forms chlorides
• Chlorine has great affinity for hydrogen


  Reacts with compounds containing hydrogen to form HCl
• Chlorine reacts with ammonia

  • Gives nitrogen and ammonium chloride with excess ammonia
  • Gives nitrogen trichloride (explosive) with excess chlorine
• Chlorine reacts with cold and dilute alkalies


  Produces a mixture of chloride and hypochlorite
• Chlorine reacts with hot and concentrated alkalies


  Gives chloride and chlorate
• Chlorine reacts with dry slaked lime

  Gives bleaching powder
• Chlorine reacts with hydrocarbons

  • Gives substitution products with saturated hydrocarbons
  • Gives addition products with unsaturated hydrocarbons
• Chlorine water on standing

  Loses its yellow colour due to formation of HCl and HOCl
• Hypochlorous acid (HOCl) formed

  Gives nascent oxygen which is responsible for oxidising and bleaching properties of chlorine
• Chlorine oxidises


  • Ferrous to ferric
  • Sulphite to sulphate
  • Sulphur dioxide to sulphur trioxide
  • Iodine to iodate
• Chlorine


  A powerful bleaching agent, bleaching action is due to oxidation