one model<\/a>, the energies of these orbitals are -20, -11, and -8 eV for S, and -18.6, -14, and -7 eV for P. Compare the energy of a S 3d<\/i> electron (-8 eV) or P 3d<\/i> electron (-7 eV) with the energy of an O 2p<\/i> electron (-14.8 eV) or a F 2p<\/i>
\nelectron (-18.1 eV). An electron that has to choose between S\/P 3d<\/i>
\nand O\/F 2p<\/i> would have a very strong preference for the low energy
\norbitals provided by O and F. In fact, the electron might be so
\npartial to O\/F that we shouldn’t say the electron is shared, we should
\nimagine an ionic bond instead.<\/p>\n\nOrbital energies have been known to chemists for decades, yet
\nmany chemists persist in drawing hypervalent structures. Why? Perhaps because the drawings
\nare cleaner. Perhaps because certain wrong ideas have so much appeal (the earth is flat, the sun rises, tobacco smoke won’t harm me because I am young and beautiful) that logic and data no longer matter. If nothing else, this is a nice illustration that scientists are human and science is not always about getting the right answer.<\/p>\n
\nHere’s what I expect you to do on Chem 201 assignments: When I ask
\nfor a Lewis structure<\/b> drawing, do not draw any exceptions to the octet rule. When any other kind of structural formula<\/b> is needed, you can draw whatever other chemists draw.<\/p>\n
\nDoes this make sense? Is there a molecule that’s bugging you? Am I
\nforcing you to break a deeply engrained habit? Come see me. Or post a
\ncomment – I think I have successfully activated them, but I won’t know
\nuntil you try to make a post.<\/p>\n","protected":false},"excerpt":{"rendered":"
This question came up after lecture and its one worth bringing to the o chem public: Should sulfuric acid be drawn with double bonds (the way I originally drew it in lecture) or with single bonds+formal charges (the way I…<\/p>\n","protected":false},"author":55,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-29","post","type-post","status-publish","format-standard","hentry","category-post-lecture"],"_links":{"self":[{"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/posts\/29","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/users\/55"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/comments?post=29"}],"version-history":[{"count":2,"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/posts\/29\/revisions"}],"predecessor-version":[{"id":5215,"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/posts\/29\/revisions\/5215"}],"wp:attachment":[{"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/media?parent=29"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/categories?post=29"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.reed.edu\/chem201202\/wp-json\/wp\/v2\/tags?post=29"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}