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Copy of Structure And Allotropes Of Sulphur
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Check us out at http://chemistry.tutorvista.com • Allotropes of Sulphur • There are a large number of allotropes of sulfur. In this respect, sulfur is second only to carbon.[1] The most common form found in nature is yellow orthorhombic α-sulfur, which contains puckered rings of S8.[1] Chemistry students may have seen plastic sulfur ; this is not an allotrope but a mixture of long chain polymeric sulfur forms, two of which have been identified as allotropes.[1] In addition to these there are other solid forms that contain sulfur rings of 6, 7, 915, 18 and 20 atoms.[1] There are also gases, S2, S3; some species only detected in the vapour phase, S4 and S5 and perhaps five or more high-pressure forms, two of which are metallic.[2] • The range of molecular allotropes possessed by sulfur can in part be ascribed to the wide range of bond lengths (180260 pm) and bond angles (90120°) exhibited by the SS bond and its strength (the unrestrained SS single bond has a high bond energy of 265 kJ mol−1).[1] • Early workers identified some forms that have later proved to be allotropes, i.e. pure forms, whilst others have proved to be mixtures.[2] Some forms have been named for their appearance, e.g. mother of pearl sulfur , or alternatively named for a chemist who was pre-eminent in identifying them, e.g. Muthmann's sulfur I or Engel's sulfur .[3] A commonly used naming system uses Greek suffixes (α, β, etc.); however, this system predates the discovery of the new forms that have been synthesised rather than prepared from elemental sulfur. • Please like our facebook page • / tutorvista Follow us at: https://plus.google.com/+tutorvista/
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