Ground-level ozoneGround-level ozone (O3), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. Ozone is also an important constituent of the stratosphere, where the ozone layer (2 to 8 parts per million ozone) exists which is located between 10 and 50 kilometers above the Earth's surface.
Dimethyl sulfideDimethyl sulfide (DMS) or methylthiomethane is an organosulfur compound with the formula . The simplest thioether, it is a flammable liquid that boils at and has a characteristic disagreeable odor. It is a component of the smell produced from cooking of certain vegetables, notably maize, cabbage, beetroot, and seafoods. It is also an indication of bacterial contamination in malt production and brewing. It is a breakdown product of dimethylsulfoniopropionate (DMSP), and is also produced by the bacterial metabolism of methanethiol.
OzonolysisIn organic chemistry, ozonolysis is an organic reaction where the unsaturated bonds are cleaved with ozone (). Multiple carbon–carbon bond are replaced by carbonyl () groups, such as aldehydes, ketones, and carboxylic acids. The reaction is predominantly applied to alkenes, but alkynes and azo compounds are also susceptible to cleavage. The outcome of the reaction depends on the type of multiple bond being oxidized and the work-up conditions. Detailed procedures have been reported.
Chromate and dichromateChromate salts contain the chromate anion, CrO42−. Dichromate salts contain the dichromate anion, Cr2O72−. They are oxyanions of chromium in the +6 oxidation state and are moderately strong oxidizing agents. In an aqueous solution, chromate and dichromate ions can be interconvertible. Potassium-chromate-sample.jpg|[[potassium chromate]] Potassium-dichromate-sample.jpg|[[potassium dichromate]] Chromates react with hydrogen peroxide, giving products in which peroxide, O22−, replaces one or more oxygen atoms.
