{"id":563,"date":"2017-08-21T10:26:57","date_gmt":"2017-08-21T10:26:57","guid":{"rendered":"http:\/\/americanboard.org\/Subjects\/chemistry\/?page_id=563"},"modified":"2017-09-08T04:32:18","modified_gmt":"2017-09-08T04:32:18","slug":"aromatics","status":"publish","type":"page","link":"https:\/\/americanboard.org\/Subjects\/chemistry\/aromatics\/","title":{"rendered":"Aromatics"},"content":{"rendered":"<div class=\"twelve columns\" style=\"margin-top: 10%;\">\n<div class=\"advance\">\n<p><a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/halogenated-hydrocarbons-and-hydrocarbon-reactions\">\u2b05 Previous Lesson<\/a>\u00a0<a class=\"button\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/organic-chemistry\">Workshop Index<\/a>\u00a0<a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/polymers\">Next Lesson \u27a1<\/a><\/p>\n<\/div>\n<p><!-- UPDATE NEXT\/PREVIOUS ABOVE --><\/p>\n<p><!-- CONTENT STARTS HERE --><\/p>\n<h1 id=\"title\">Aromatics<\/h1>\n<h4>Objective<\/h4>\n<p>In this lesson we will review how to name aromatic hydrocarbons.<\/p>\n<h4>Previously we covered&#8230;<\/h4>\n<ul>\n<li>Naming halogenated hydrocarbons<\/li>\n<li>Substitution reactions of hydrocarbons<\/li>\n<li>Addition reactions of unsaturated hydrocarbons<\/li>\n<li>Dehydrogenation of alkanes<\/li>\n<li>Elimination reactions<\/li>\n<\/ul>\n<section>\n<h3>Aromatics<\/h3>\n<p><abbr title=\"A special group of unsaturated cyclic hydrocarbons with delocalized electrons\">Aromatics<\/abbr> are a special group of unsaturated cyclic hydrocarbons with delocalized electrons.The simplest is benzene or 1,3,5-cyclohexatriene.<\/p>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/s5_p2_clip_image002.jpg\" alt=\"1,3,5-cyclohexatriene\" width=\"215\" height=\"68\" \/><\/center><\/p>\n<p>The circle represents the delocalized nature of the electrons where the double bonds are resonating between the carbons of the ring.<\/p>\n<h3>Naming Aromatics<\/h3>\n<p>When naming molecules containing a benzene ring, the benzene ring becomes the main \u201cChain\u201d and thus the last name. The rules for naming branches on cyclic hydrocarbons are the same with aromatics. When there are branches attached to a cyclic molecule, name the ring structure, add the name(s) of the branches, then tell the location(s) of the branches. When there is only one branch, it is always be located on the number one carbon (any one could be designated as number one), so no location number is needed.<\/p>\n<table>\n<tbody>\n<tr>\n<td>\n<div align=\"center\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics2.methyl_benzene.gif\" alt=\"methyl benzene\" width=\"91\" height=\"125\" \/><\/div>\n<\/td>\n<td>methyl benzene<\/td>\n<\/tr>\n<tr>\n<td>\n<div align=\"center\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics2.ethyl_benzene.gif\" alt=\"ethyl benzene\" width=\"102\" height=\"125\" \/><\/div>\n<\/td>\n<td>ethyl benzene<\/td>\n<\/tr>\n<tr>\n<td>\n<div align=\"center\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics2.propyl_benzene.gif\" alt=\"propyl benzene\" width=\"141\" height=\"125\" \/><\/div>\n<\/td>\n<td>propyl benzene<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>When multiple branches are located on a benzene as with all cyclic hydrocarbons you can start the numbering with any carbon of the ring and go in either a clockwise or counterclockwise direction.<\/p>\n<p>With aromatics when a benzene ring has branches in the 1st and 2nd positions they are referred to as being in the \u201cortho-\u201c position (\u201c<em>o<\/em>-\u201c is used), when in the 1st and 3rd positions it is referred to as being in the \u201cmeta-\u201c position (\u201c<em>m<\/em>-\u201c is used) and when in the 1st and 4th positions it is referred to as being in the \u201cpara-\u201c position (\u201c<em>p<\/em>-\u201c is used).<\/p>\n<table>\n<tbody>\n<tr>\n<td valign=\"top\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics3.o-dimethylbenzene.gif\" width=\"200\" height=\"200\" \/><\/td>\n<td valign=\"middle\">1,2-dimethylbenzene,<br \/>\northo-dimethylbenzene or<br \/>\n<em>o<\/em>-dimethylbenzene<\/td>\n<\/tr>\n<tr>\n<td valign=\"top\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics3.m-dimethylbenzene.gif\" width=\"200\" height=\"200\" \/><\/td>\n<td valign=\"middle\">1,3-dimethylbenzene,<br \/>\nmeta-dimethylbenzene or<br \/>\n<em>m<\/em>-dimethylbenzene<\/td>\n<\/tr>\n<tr>\n<td valign=\"top\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics3.p-dimethylbenzene.gif\" width=\"107\" height=\"213\" \/><\/td>\n<td valign=\"middle\">1,4-dimethylbenzene,<br \/>\npara-dimethylbenzene or<br \/>\n<em>p<\/em>-dimethylbenzene<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The delocalization of the electrons in the benzene ring causes great stability and therefore makes it less reactive than most other alkenes and alkynes. Also, its non-polar nature had made it a frequently used solvent. However, it has been found to be both a poison and a carcinogen, so its usage has declined.<\/p>\n<p>When benzene is a branch it is called \u201cphenyl-.\u201d<\/p>\n<section class=\"question\">\n<h4>Question<\/h4>\n<p>What is the name of the following molecule?<\/p>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics5.1_3_bromochlorobenzene.gif\" width=\"157\" height=\"167\" \/><\/center><\/p>\n<ol>\n<li>bromochlorobenzene<\/li>\n<li>1,3-bromochlorobenzene<\/li>\n<li>m-bromochlorobenzene<\/li>\n<li>B and C are correct<\/li>\n<\/ol>\n<p><a class=\"button button-primary q-answer\"> Reveal Answer <\/a><\/p>\n<p class=\"q-reveal\">The correct answer is D. Both B and C are correct. Having branches in the 1 and 3 position of a benzene ring are referred to as being \u201cmeta-\u201c which is abbreviated as \u201c<em>m<\/em>-.\u201d<\/p>\n<\/section>\n<section class=\"question\">\n<h4>Question<\/h4>\n<p>What is the name of the following molecule?<\/p>\n<p><center><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/americanboard.org\/Subjects\/Images\/chemistry\/img\/OrganicChemistry\/aromatics5.1_chloro_3_methylbenzene.gif\" width=\"150\" height=\"159\" \/><\/center><\/p>\n<ol>\n<li>1-chloro-3-methylbenzene<\/li>\n<li>benzenechloromethyl<\/li>\n<li>chloromethylbenzene<\/li>\n<li>methylchlorobenzene<\/li>\n<\/ol>\n<p><a class=\"button button-primary q-answer\"> Reveal Answer <\/a><\/p>\n<p class=\"q-reveal\">The correct answer is A. It could also be called, <em>m<\/em>-chloromethylbenzene or meta-chloromethyl benzene.<\/p>\n<\/section>\n<\/section>\n<p><!-- CONTENT ENDS HERE --><\/p>\n<p><!-- UPDATE NEXT\/PREVIOUS BELOW --><\/p>\n<div class=\"advance\"><a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/halogenated-hydrocarbons-and-hydrocarbon-reactions\">\u2b05 Previous Lesson<\/a>\u00a0<a class=\"button\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/organic-chemistry\">Workshop Index<\/a>\u00a0<a class=\"button button-primary\" href=\"http:\/\/americanboard.org\/Subjects\/chemistry\/polymers\">Next Lesson \u27a1<\/a><\/div>\n<p><a class=\"backtotop\" href=\"#title\">Back to Top<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u2b05 Previous Lesson\u00a0Workshop Index\u00a0Next Lesson \u27a1 Aromatics Objective In this lesson we will review how to name aromatic hydrocarbons. Previously we covered&#8230; Naming halogenated hydrocarbons Substitution reactions of hydrocarbons Addition reactions of unsaturated hydrocarbons Dehydrogenation of alkanes Elimination reactions Aromatics Aromatics are a special group of unsaturated cyclic hydrocarbons with delocalized electrons.The simplest is benzene [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-563","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages\/563","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/comments?post=563"}],"version-history":[{"count":7,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages\/563\/revisions"}],"predecessor-version":[{"id":621,"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/pages\/563\/revisions\/621"}],"wp:attachment":[{"href":"https:\/\/americanboard.org\/Subjects\/chemistry\/wp-json\/wp\/v2\/media?parent=563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}