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Ozone is an unstable compound. Pure ozone decomposes explosively, while ozonised oxygen decomposes slowly at room temperature. Decomposition is instantaneous at about 573 K.
The decomposition is accelerated by the presence of manganese dioxide, platinum black and copper oxide etc.
Ozone acts as a powerful oxidizing agent due to the reaction,
The nascent oxygen formed due to its decomposition is responsible for the oxidation of a number of substances. Typical oxidation reactions are given below:
It oxidises lead sulphide to lead sulphate
It liberates iodine from a solution of potassium iodide
Halogen acids are oxidized to corresponding halogens (e.g. hydrochloric acid is oxidized to chlorine.)
It oxidizes sulphur dioxide to sulphur trioxide
It oxidizes moist iodine to iodic acid
It oxidizes potassium ferrocyanide solution to potassium ferricyanide
It oxidizes acidified stannous chloride to stannic chloride
Silver metal when warmed with ozone gets blackened due to reduction of the oxide formed in the initial stages of the reaction.
When ozone is passed through mercury, it loses its meniscus and sticks to the glass due to the formation of mercurous oxide. This is called tailing of mercury. The meniscus can be restored by shaking it with water.
Ozone acts as a good bleaching agent for vegetable coloring matter (due to its oxidizing nature)
Ozone reduces peroxides to oxides and in turn gets reduced to oxygen. For example, with H2O2 and BaO2, it gives H2O and BaO respectively.
Ozonides are addition products, which are formed when unsaturated organic compounds containing double bond react with ozone.
These ozonides are decomposed by water or dilute acids giving aldehydes and hydrogen peroxide in most of the cases.
The position of the double bond can be located in the original unsaturated molecule by this reaction. This reaction is termed 'ozonolysis'.
Ozone is used
Either of these three tests help in identifiying ozone.
This material is based upon work supported by the National Science Foundation under Grant Number 1246120