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Perfluoroalkanes are very stable because of the strength of the carbon–fluorine bond, one of the strongest in organic chemistry. [4] Its strength is a result of the electronegativity of fluorine imparting partial ionic character through partial charges on the carbon and fluorine atoms, which shorten and strengthen the bond (compared to carbon-hydrogen bonds) through favorable covalent ...
Carbon–fluorine bonds can have a bond dissociation energy (BDE) of up to 130 kcal/mol. [2] The BDE (strength of the bond) of C–F is higher than other carbon–halogen and carbon–hydrogen bonds. For example, the BDEs of the C–X bond within a CH 3 –X molecule is 115, 104.9, 83.7, 72.1, and 57.6 kcal/mol for X = fluorine, hydrogen ...
At least 17,000 metric tons of fluorine are produced each year. It costs only $5–8 per kilogram as uranium or sulfur hexafluoride, but many times more as an element because of handling challenges. Most processes using free fluorine in large amounts employ in situ generation under vertical integration. [186]
Graphs of abundance vs atomic number. Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow. Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.
Fluorite mining (the main source of fluorine) was estimated in 2003 to be a $550 million industry, extracting 4.5 million tons per year. [4] Mined fluorite is separated into two main grades, with about equal production of each. Acidspar is at least 97% CaF 2; metspar is much lower purity, 60–85%.
The only chemicals known to affect these carbon-fluorine bonds are highly reactive metals like the alkali metals, at higher temperatures such metals as aluminium and magnesium, and fluorinating agents such as xenon difluoride and cobalt(III) fluoride. [22] At temperatures above 650–700 °C (1,200–1,290 °F) PTFE undergoes depolymerization. [23]
As a result, the physical and chemical properties of organofluorines can be distinctive in comparison to other organohalogens. The carbon–fluorine bond is one of the strongest in organic chemistry (an average bond energy around 480 kJ/mol [ 1 ]). This is significantly stronger than the bonds of carbon with other halogens (an average bond ...
In Earth's atmosphere, carbon dioxide is a trace gas that plays an integral part in the greenhouse effect, carbon cycle, photosynthesis and oceanic carbon cycle. It is one of three main greenhouse gases in the atmosphere of Earth. Water vapor is the primary greenhouse gas, as of 2010, contributing 50% of the greenhouse effect, followed by ...