Properties of Ozone

Ozone (O3) is the triatomic, allotropic form of oxygen (O2). It is an unstable gas with a pungent odor. Since ozone is unstable, it must be generated at the point of application.

The Ozone molecule, having a molecular weight of 48, is made up of three oxygen atoms bound by equal oxygen-oxygen bonds at an obtuse angle of 116o49’. This structure is inherently unstable and is the reason for ozone’s powerful oxidizing ability. Ozone has approximately 150% the oxidizing potential of chlorine. The physical properties of ozone and comparative oxidizing potentials for other chemical oxidants are presented in Table 1 and Table 2, respectively.

Table 1Physical Constants of Ozone     Table 2Comparative Oxidizing Potentials,25oC Volts
Molecular weight, g/g-mol 48.0   Fluorine (F2) 2.87
Boiling point, oC -111.9   Ozone (O3) 2.07
Melting point, oC -193   Hydrogen Peroxide (H2O2) 1.78
Gas density, 0oC grams/liter 2.144   Potassium Permanganate (KMnO4) 1.70
Critical temperature, oC -12.1   Hyprobromous Acid (HOBr) 1.59
Critical pressure, atm. 54.6   Hypochlorous Acid (HOCl) 1.49
Critical volume, cc/mol 147.1   Chlorine (Cl2) 1.36
      Chlorine dioxide (ClO2) 1.27
      Oxygen (O2) 1.23
      Chromic Acid (H2CrO4) 1.21
      Bromine (Br2) 1.09
      Nitric Acid (HNO3) 0.94
      Iodine (I2) 0.54