Ka Values and Acid Strength
Like glacial acetic acid. That is why the pKa is so useful, since the ratio of H+ and A- is always dependant on the denominator of HA, which I. In organic chemistry, an alkane, or paraffin is an acyclic saturated hydrocarbon. In other words . The first four names were derived from methanol, ether, propionic acid and butyric acid, . There are two determinants for the strength of the van der Waals forces: . The general equation for complete combustion is: C nH2n+2. Sulfur or sulphur is a chemical element with symbol S and atomic number It is abundant The greatest commercial use of the element is the production of sulfuric acid for sulfate Disulfides, S–S bonds, confer mechanical strength and insolubility of the protein This conversion requires several organosulfur cofactors.
The chain of reactions is eventually terminated by radical or ion recombination. Isomerization and reformation[ edit ] Dragan and his colleague were the first to report about isomerization in alkanes. In isomerization, the alkanes become branched-chain isomers.
Alkane - Wikipedia
In other words, it does not lose any carbons or hydrogens, keeping the same molecular weight. Both of these processes raise the octane number of the substance. Butane is the most common alkane that is put under the process of isomerization, as it makes many branched alkanes with high octane numbers. Alkanes can be chlorosulfonated and nitratedalthough both reactions require special conditions. The fermentation of alkanes to carboxylic acids is of some technical importance. In the Reed reactionsulfur dioxidechlorine and light convert hydrocarbons to sulfonyl chlorides.
Nucleophilic Abstraction can be used to separate an alkane from a metal. Alkyl groups can be transferred from one compound to another by transmetalation reactions. Occurrence of alkanes in the Universe[ edit ] Methane and ethane make up a tiny proportion of Jupiter 's atmosphere Extraction of oil, which contains many different hydrocarbons including alkanes Alkanes form a small portion of the atmospheres of the outer gas planets such as Jupiter 0.
Methane and ethane have also been detected in the tail of the comet Hyakutake. Chemical analysis showed that the abundances of ethane and methane were roughly equal, which is thought to imply that its ices formed in interstellar space, away from the Sun, which would have evaporated these volatile molecules.
Occurrence of alkanes on Earth[ edit ] Traces of methane gas about 0. These hydrocarbons were formed when marine animals and plants zooplankton and phytoplankton died and sank to the bottom of ancient seas and were covered with sediments in an anoxic environment and converted over many millions of years at high temperatures and high pressure to their current form.
Natural gas resulted thereby for example from the following reaction: They have formed over millions of years and once exhausted cannot be readily replaced. The depletion of these hydrocarbons reserves is the basis for what is known as the energy crisis.
Methane is also present in what is called biogasproduced by animals and decaying matter, which is a possible renewable energy source. Alkanes have a low solubility in water, so the content in the oceans is negligible; however, at high pressures and low temperatures such as at the bottom of the oceansmethane can co-crystallize with water to form a solid methane clathrate methane hydrate.
Although this cannot be commercially exploited at the present time, the amount of combustible energy of the known methane clathrate fields exceeds the energy content of all the natural gas and oil deposits put together. Methane extracted from methane clathrate is, therefore, a candidate for future fuels. Acyclic alkanes occur in nature in various ways. Bacteria and archaea Methanogenic archaea in the gut of this cow are responsible for some of the methane in Earth's atmosphere. Certain types of bacteria can metabolize alkanes: The energy is released by the oxidation of hydrogen: The methane output of cattle and other herbivoreswhich can release 30 to 50 gallons per day,  and of termites is also due to methanogens.
They also produce this simplest of all alkanes in the intestines of humans. Methanogenic archaea are, hence, at the end of the carbon cyclewith carbon being released back into the atmosphere after having been fixed by photosynthesis.
It is probable that our current deposits of natural gas were formed in a similar way. Some specialized yeasts, e. A man carrying sulfur blocks from Kawah Ijena volcano in East Java, Indonesia, 32S is created inside massive stars, at a depth where the temperature exceeds 2. Sulfur, usually as sulfide, is present in many types of meteorites. Ordinary chondrites contain on average 2.
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It is normally present as troilite FeSbut there are exceptions, with carbonaceous chondrites containing free sulfur, sulfates and other sulfur compounds. Elemental sulfur can be found near hot springs and volcanic regions in many parts of the world, especially along the Pacific Ring of Fire ; such volcanic deposits are currently mined in Indonesia, Chile, and Japan. Native sulfur may be produced by geological processes alone.
Fossil-based sulfur deposits from salt domes were until recently the basis for commercial production in the United States, Russia, Turkmenistan, and Ukraine.
Such sources are now of secondary commercial importance, and most are no longer worked. Common naturally occurring sulfur compounds include the sulfide mineralssuch as pyrite iron sulfidecinnabar mercury sulfidegalena lead sulfidesphalerite zinc sulfide and stibnite antimony sulfide ; and the sulfates, such as gypsum calcium sulfatealunite potassium aluminium sulfateand barite barium sulfate.
On Earth, just as upon Jupiter's moon Io, elemental sulfur occurs naturally in volcanic emissions, including emissions from hydrothermal vents. Sulfur forms stable compounds with all elements except the noble gases. Bucholz, but the cause of the color and the structure of the polycations involved was only determined in the late s. When dissolved in water, hydrogen sulfide is mildly acidic: Zig-zag b and straight c S chains inside double-wall CNTs  Oxides, oxoacids and oxoanions[ edit ] The principal sulfur oxides are obtained by burning sulfur: Sulfur forms sulfur oxoacidssome of which cannot be isolated and are only known through the salts.
Sulfuric acid and SO3 combine to give oleum, a solution of pyrosulfuric acid H2S2O7 in sulfuric acid. Halides and oxyhalides[ edit ] Several sulfur halides are important to modern industry. Sulfur hexafluoride is a dense gas used as an insulator gas in high voltage transformers ; it is also a nonreactive and nontoxic propellant for pressurized containers. Sulfur tetrafluoride is a rarely used organic reagent that is highly toxic.