What are the chemical properties of chlorine?

Chlorine is a chemical element with symbol of Cl and the atomic number is 17. Among all the halogens, it is the second lightest. In the periodic table it appears between fluorine and Bromine. It is extremely reactive and strong oxidising agent and has a strong electron affinity and also high electronegativity.

Atomic Group – 17 (HALOGENS)

Period – 3

Block is p-block

Appearance is Yellow Green and pale

Crystal structure is Orthorhombic

Magnetic order is diamagnetic

The natural occurrence is primordial and it is a gas at STP phase.

As an element it was introduced by Humphrey Davy.

Because Chlorine is highly reactive all the chlorine in the Earth is in the form of ionic chloride compounds, and which includes Table Salt as well. It is highly abundant in nature. It is one of the most abundant after Fluorine. Chloride reserves are available in the nature in the crusted seawater.

Chemists all over the world perform experiments on Chlorine and one of them commonly is heating of Chloride Salts like Ammonium Chloride and Sodium Chloride (Salt) and also like hydrogen chloride and Aqua Regia. The nature of free chlorine gas when it is a separate substance was discovered by Jan Baptist Van Helmont in 1630. Carl Wilhelm Scheele described Chlorine in 1774 and said it was an oxide of a new element. Gas might be a pure element and it was confirmed by Humphrey Davy.

We know Chlorine is very necessary for all the species of life. Some chlorine compounds are rare in living organisms and chlorine containing organic molecules such as chloflourocarbons are responsible for ozone layer depletion. Some small amount of elemental chlorine is made by chlorine oxidation to hypochlorite in the neutrophils as part of immune system.

How do we make Elemental Chlorine? This is by brine by the process by electrolysis in the chlorine alkali process. The highly oxidising property of Chlorine made it to the development of bleaches and disinfectants and a reagent for many important process in the chemical industry. Chlorine is used also to make PVC – polyvinyl Chloride and for plastics and also other end products which do not have the element. As a disinfectant these chlorine compounds are used as a sanitation material for swimming pools. These chlorine is also very dangerous in reality and poisonous for most of the living organisms. In the field of Chemical Warfare, chlorine was first used in WW I as a weapon used as poison gas.

Chemical Properties:

  1. The properties of Chlorine is same to the properties of Bromine, Iodine and Fluorine. They are intermediate between the first two. They have electronic configuration with 7 electrons in the third and most outer shell acting as the valence electrons.
  2. Chloine just like halogens have one electron short on the octet and is a very strong oxidising agent. It reacts with almost all the elements because it has to complete its outer shell.
  3. It has intermediate electronegativity between fluorine and Bromine. It is a weak oxidising agent. Weaker than fluorine and stronger than Bromine.
  4. The melting and Boiling point of Chlorine is – It melts at – 101 degree C and boils at -34.0 Degree C. The density of fusion and vaporisation of chlorine are again in between Fluorine and Bromine. They have diatomic molecular structure and hence they vaporise fairly low. Chlorine is distinctly hello green but pale. This colour for Chlorine is result of electron transition between the highest occupied molecular orbital and lowest vacant molecular orbital. The colours usually fades away as temperature becomes low. So solid Chlorine at -195 Degree C is almost no colour.
  5. Chlorination leads to higher oxidation than bromination and iodination but lower than fluorination. Chlorine reacts with compounds to form bonds like M- Cl bonds, M-C bonds etc
  6. We can see standard electrode potentials for Chlorine of the X2/X couples. This trend however is not seen for the bond energies because Fl is singular due to its small size and low polarasibilty and it has inability to show hyper valence.

Applications Of Chlorine:

  1. Na CL is the most common used chlorine compound. This is the main source of Chlorine as in the Chemical industry. We have about more than 1000 chlorine containing compounds that are commercial used and for example- Vinyl Chloride, Ethanes, PVC which is Polyvinyl Chloride etc.
  2. Chlorine produces 63 percent of all the elements used in manufacture of organic compounds and 10 percent of inorganic chlorine compounds. They are also extensively used for bleaches and disinfection products and henceforth.
  3. They are used extensively for Sanitation, Disinfection and Antisepsis.