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Revision as of 11:18, 3 August 2015
Contents
Properties
Chemical
Ozone is a powerful oxidant, much more powerful than dioxygen.
Ozone will oxidize most metals (except noble metals) to oxides of the metals in their highest oxidation state. It will also oxidize nitrogen oxides up until dinitrogen pentoxide
- NO + O3 → NO2 + O2
- NO2 + O3 → NO3 + O2
- NO3 + NO2 → N2O5
Solid nitronium perchlorate can be made from NO2, ClO2, and O3:
- 2 NO2 + 2 ClO2 + 2 O3 → 2 NO2ClO4 + O2
It will also oxidize sulphides to sulphates and sulfur and sulfur oxides to sulfuric acid in the presence of water.
- PbS + 4 O3 → PbSO4 + 4 O2
- S + H2O + O3 → H2SO4
Ozone reacts with carbon to form carbon dioxide, even at room temperature:
- C + 2 O3 → CO2 + 2 O2
This is useful when cleaning glassware that have traces of carbon (such as graphite) that are hard to clean.
Ozone does not react with ammonium salts, but it will oxidize ammonia to ammonium nitrate:
- 2 NH3 + 4 O3 → NH4NO3 + 4 O2 + H2O
Ozone also reacts with organic compounds to form various substances.
Physical
Ozone is a pale blue gas with a distinctively pungent smell commonly described as that of copy machines, due to commercial copy machine producing small amounts. Its liquid form is dark blue and it forms a violet-black solid at extremely low temperatures. It is also unstable at high concentrations, decaying to ordinary diatomic oxygen. It has a varying length half-life, in a sealed chamber at standard conditions, with fan moving the gas, ozone has a half-life of a day.
Availability
Ozone is unstable, so it must be generated in situ.
Preparation
Ozone can be generated from electric discharges in air. Ozone generators work on this principle. However such method also generates nitrous oxides, as air is 78% nitrogen.
Another method of generating ozone is decomposition of various peroxide compounds in acidic solution. An example is decomposition of barium peroxide in sulfuric acid.
Projects
- Making sulfuric acid
- Ozonides synthesis
Handling
Safety
Ozone at concentrations higher than 0.1 ppm in air is dangerous, as it will oxidize organic material indiscriminately. Ground level ozone can harm lung function and irritate the respiratory system.[1] Ozone reacts with compounds lining the lungs to form specific, cholesterol-derived metabolites that are thought to facilitate the build-up and pathogenesis of atherosclerotic plaques (a form of heart disease).[2]
Ozone will react with organic materials to form ozonides, that are explosive.
Storage
Ozone will decompose after several hours and has to be made in situ.
Disposal
Ozone will decompose to normal oxygen in open air.
See also
- Oxygen, for a more general discussion of the element
- Singlet oxygen
References
- ↑ http://www.cdc.gov/niosh/idlh/10028156.html
- ↑ http://www.sciencedirect.com/science/article/pii/S0891584904003454
