Search results
Results from the WOW.Com Content Network
Most of the ozone production occurs in the tropical upper stratosphere and mesosphere. The total mass of ozone produced per day over the globe is about 400 million metric tons. The global mass of ozone is relatively constant at about 3 billion metric tons, meaning the Sun produces about 12% of the ozone layer each day. [1]
One study finds significant positive associations between chronic ozone and all-cause, circulatory, and respiratory mortality with 2%, 3%, and 12% increases in risk per 10 ppb [93] and report an association (95% CI) of annual ozone and all-cause mortality with a hazard ratio of 1.02 (1.01–1.04), and with cardiovascular mortality of 1.03 (1.01 ...
A chlorate candle, or an oxygen candle, is a cylindrical chemical oxygen generator that contains a mix of sodium chlorate and iron powder, which when ignited smolders at about 600 °C (1,100 °F), producing sodium chloride, iron oxide, and oxygen at a fixed rate of about 6.5 man-hours per kilogram of the mixture.
Ozone depletion consists of two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth's atmosphere, [citation needed] and a much larger springtime decrease in stratospheric ozone (the ozone layer) around Earth's polar regions. [1] The latter phenomenon is referred to as the ...
The ozone depletion potential (ODP) of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane (R-11 or CFC-11) being fixed at an ODP of 1.0. Chlorodifluoromethane (R-22), for example, has an ODP of 0.05. CFC 11, or R-11 has the maximum potential amongst chlorocarbons because of the ...
In June to August, photochemical ozone production causes very high concentrations over the East Coast of the US and China. Ground-level ozone ( O 3 ), 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 ...
When the solution has stopped absorbing ozone, the excess ozone oxidizes the iodide to iodine, which can easily be observed by its violet color. [6] For closer control of the reaction itself, an indicator such as Sudan Red III can be added to the reaction mixture. Ozone reacts with this indicator more slowly than with the intended ozonolysis ...
While there are many abiotic sources and sinks for O 2, the presence of the profuse concentration of free oxygen in modern Earth's atmosphere and ocean is attributed to O 2 production from the biological process of oxygenic photosynthesis in conjunction with a biological sink known as the biological pump and a geologic process of carbon burial involving plate tectonics.