{"id":174,"date":"2017-10-04T14:55:17","date_gmt":"2017-10-04T14:55:17","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/?post_type=chapter&#038;p=174"},"modified":"2018-09-28T19:58:17","modified_gmt":"2018-09-28T19:58:17","slug":"formal-charges","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/chapter\/formal-charges\/","title":{"raw":"Formal Charges","rendered":"Formal Charges"},"content":{"raw":"<div class=\"elm-header\"><\/div>\r\n<div id=\"elm-main-content\" class=\"elm-content-container\">\r\n<div id=\"mt-toc-container\" class=\"bc-aside aside\">\r\n<div class=\"textbox learning-objectives\">\r\n<h3>Objectives<\/h3>\r\n<div>\r\n<div id=\"skills\">\r\n\r\nAfter completing this section, you should be able to\r\n<ol>\r\n \t<li>determine which atoms, if any, of a given simple compound (e.g., HNO<sub>3<\/sub>, CH<sub>2<\/sub>=N=N, CH<sub>3<\/sub>-NC) carry formal charges, and apply the principles used to more complex examples. [The Lewis structure, Kekul\u00e9 structure or molecular formula would normally be provided.]<\/li>\r\n \t<li>draw the Lewis structure, the Kekul\u00e9 structure, or both, of a compound of known molecular formula in which certain atoms possess a formal charge<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Key Terms<\/h3>\r\n<div>\r\n<div>\r\n\r\nMake certain that you can define, and use in context, each of the key terms listed below.\r\n<ul>\r\n \t<li>dipolar<\/li>\r\n \t<li>formal charge<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<div>\r\n<div id=\"note\">\r\n<div class=\"textbox\">\r\n<p class=\"boxtitle\"><strong>Study Notes<\/strong><\/p>\r\nToo much emphasis can easily be placed on the concept of formal charge, and the mathematical approach used in the textbook is hard to justify. In this course, you will certainly need to be able to recognize whether a given species carries a charge (i.e., is an ion), but you will not often encounter dipolar molecules, such as the textbook example nitromethane.\r\n\r\n<\/div>\r\n<\/div>\r\n<div id=\"section_1\">\r\n<h3 class=\"editable\">Formal Charges<\/h3>\r\nIt is sometimes possible to write more than one Lewis structure for a substance that does not violate the octet rule, as we saw for CH<sub class=\"subscript\">2<\/sub>O, but not every Lewis structure may be equally reasonable. In these situations, we can choose the most stable Lewis structure by considering the <a class=\"glossterm\">formal <\/a><a class=\"glossterm\">charge<\/a> on the atoms, which is the difference between the number of valence electrons in the free atom and the number assigned to it in the Lewis electron structure. The formal charge is a way of computing the charge distribution within a Lewis structure; the sum of the formal charges on the atoms within a molecule or an ion must equal the overall charge on the molecule or ion. A formal charge does <em class=\"emphasis\">not<\/em> represent a true charge on an atom in a covalent bond but is simply used to predict the most likely structure when a compound has more than one valid Lewis structure.\r\n\r\nTo calculate formal charges, we assign electrons in the molecule to individual atoms according to these rules:\r\n<ul class=\"itemizedlist editable block\">\r\n \t<li>Nonbonding electrons are assigned to the atom on which they are located.<\/li>\r\n \t<li>Bonding electrons are divided equally between the bonded atoms.<\/li>\r\n<\/ul>\r\nFor each atom, we then compute a formal charge:\r\n<p style=\"text-align: center\"><strong><img src=\"https:\/\/chem.libretexts.org\/LibreTexts\/Sonoma_State_University\/SSU_Chem_335A\/Material_for_Exam_1\/Unit_2%3A_Polar_Covalent_Bonds%3B_Acids_and_Bases\/denied:data:image\/png;base64,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#fixme\" alt=\"\" \/>formal\u00a0charge\u00a0=\u00a0valence\u00a0e<sup>\u2212\u00a0<\/sup>\u2212(free\u00a0atom)(non\u2212bonding\u00a0e<sup>\u2212\u00a0<\/sup>+\u00a0bonding\u00a0e<sup>-<\/sup><span style=\"font-size: 13.3333px\">\/2<\/span>)<\/strong><\/p>\r\n<p class=\"para editable block\">To illustrate this method, let\u2019s calculate the formal charge on the atoms in ammonia (NH<sub class=\"subscript\">3<\/sub>) whose Lewis electron structure is as follows:<\/p>\r\n\r\n<div class=\"informalfigure large block\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145254\/768e2d063688200c5482e54c7905ab81.jpg\" alt=\"768e2d063688200c5482e54c7905ab81.jpg\" width=\"550px\" height=\"88px\" \/><\/div>\r\nA neutral nitrogen atom has five valence electrons (it is in group 15). From its Lewis electron structure, the nitrogen atom in ammonia has one lone pair and shares three bonding pairs with hydrogen atoms, so nitrogen itself is assigned a total of five electrons [2 nonbonding e<sup class=\"superscript\">\u2212<\/sup>\u00a0+\u00a0(6 bonding e<sup class=\"superscript\">\u2212<\/sup>\/2)]. Substituting into the formula, we obtain\r\n<p style=\"text-align: center\">formalcharge(N)=5\u00a0valence\u00a0e<sup>\u2212<\/sup>\u2212(2\u00a0non\u2212bonding\u00a0e<sup>\u2212<\/sup>\u00a0+\u00a06\u00a0bonding\u00a0e<sup>\u2212<\/sup>\/2)=0<img src=\"https:\/\/chem.libretexts.org\/LibreTexts\/Sonoma_State_University\/SSU_Chem_335A\/Material_for_Exam_1\/Unit_2%3A_Polar_Covalent_Bonds%3B_Acids_and_Bases\/denied:data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAn4AAAApCAIAAAAkprNRAAAQWUlEQVR4nO2d72siSRrH73+qV0UjTb9pMU1kFTdCxzBmMUgnDCLpA3PJICPsjksSLjvNuuy4I5vZjXdhcbk+xt0RYUP2PC4ONIvMZUDmiAmD4EIzsPim3tW96LbTavszHaOxPu\/G1FRXV2t966l66tt\/wgQCgUAgECbIn+66AQQCgUAgzBdEegkEAoFAmChEegnzDnp78rOi3nUrCIQhqJeL5fpdN4JgA0R6CXMNUiQ\/G8oo6K4bQhgRdPmLtO7hha01LxM+rHb++dVjzyILAb1xXLv5tV5\/GWAdEACfVMEYY9x8U8ydvL2L7wxSJD8VzHTdLmHWINJLmGPqssi64wUSRswcdVlk6GBaQfjVNgUAkzjpKnKe8l+L5Y3Jx6BxlfffhyF0J4q2L5W8\/yWz38nRvz+0F2oWdhgmXiSTxdmGSC9hXkGK5KfcuyUyhs0exTgNYOiwhjHGzcbFRaPZVQTlIgDQOwV7Hq9y4AG0KE\/HvgQqJTlIQt\/ZhkgvYU6ppPyQi9sfuRBuH+XAAwBgFvjV6JrbsbB5bKFCZnW+MWpWANMkdqos0iCYqd11OwhjQ6SXMJfUswKkw0dTM5YSRkEWAQCAe1JCGFfTAQD8qfOOIucpPwDAsRiKrrkdC59p67PobS6x6uGFrSjPOh6kFISU1DrvZSAb200EAg+jPEN5vzhr1dF888M271kVVhYcFATc7hnGSEl9wq8s0VQk9zvGuC5vry65IRVK7D4MhKJrbordzNWMRjTL6fXFxRVhZWFhiee3\/vG+vY3NNz9sBxYDwtaa2xHq3q7uSzUdAFCUyZLNrEKklzCPlPc4wMTyJOSdTWQRAGP9VxZB956umhUA4Hbyl0gr4E+dIyW1TEH\/QbmJ9eVo\/9OvRDZ+nA4CoO0bY1kEgI4XMdb2I6D28fXadTUd9Eun2Q0I\/akKxhXJH8wcxWkAuJ1CHeOK5ANGMNpVQXvGl5rfZiEj5i4RxvUXoZHzwdTjDWgx5SDMCER6CfMHKuzQesxEmEWUA48hkboO6\/9oUYzTLW0+T\/kBYBL\/PN6A19MtNSsAQO\/8eHX1vxeCIeOlpBNooqopm\/5xRfLpwtlsXDQq6QDQF0yajYvGL0lnS\/nVrACMS3RW0LFeXU0HAADOB3\/eikWCQWE3N3LCNCrs0MD5pDRy7xGmASK9hLkDySIEJEd0hkGyCIFjp4Axto56z1P+VpTZ0sPjmOmokXq8AQETydW0qvTPy3scgP6Uol41mvkYbG0V1zJBAHxSuXHRaBoLJpeNKxVhPdDlds+MSlt\/yl9fr5YJtsoYyCK4ad6W1vSOOQdhRiDSS5g78jE4PdmqhHFAxTijR3wVyQeY0GH7enMtE9RECSkHPsCEMgoq73EttUbKgQ+y4YyC9GwsLSA9T\/kBHT4qSH73\/lkp6dRrePtNEAImcZwOcLtnuBinAffkNL\/j3jiu6qqqT+PyMQi4J4Wc6I7karizgo6pXkXyGZMH3CxLa+IPV6P2gjarsDhXRZh+iPTaT73w9Iuf3w8up3GZ339OVj4nSSnptC\/1lXBHNMvp9QXGu7qyuLi6m7\/s\/AUhJfWA8a4JvGc18cObZusjB8tHo6se3ljgrT5bBsyGliGNigkWMgv86m6hjnFd3l5wuNceBgKbfwmzkGGXIsdVjKuHIYpmF\/nNIwVhjF9tU7B1QK3jT0YFLGUV4CIlE2ZZPrr1542Q8Jf06TiHyyuSz8ajy3PDaCP06PxRPnwqD8qau4H0IiUTcjudDj3XbwJU\/xbzu3qcn+\/i9ZcBhgIABNITzWLtNGl4\/\/eoi3VAAAAIH\/3eahnrgABQjIvfL6G6LNp1Qv7dry\/\/VVURxrjZeF28od3OSL09Q2hxitVNISWz7nG5GAo6Fi3Pq9wp99Se6f6jHHhubaqXj0EANo4\/DC45BOhtdnNxcSUaXVlk+f37Gg\/YbaNTLyR4l4t1QIoxOm0Yz7HxpbeWCQKaYWArLWEymLInBoJyETDhLT01H2O6z4rmYxSEwHwCopYJmu5ClUXali0b7cwFAAAAyqvPvW\/CKL09M+RjEFgdiUSlJMeIcl3LTO3am5sCZtCeaXSQqnbbY8wcan6bhTCS+4BRKckZcbXtVCSfbZPj8h7Xyj2spgMAxvJ21DplWI\/QuJLyw75DsJqPMVajRj0rUH5JQbguiwwAcONYj0Mrkq\/\/weuxpRflIgD4JEVtqBOUNotMwd6Ukk6bYoRhqaYDFkNjKen0Jfc2IDDSEZEsUm3T4FLSaQTFN0AWge\/Rd7lc8fWVHU9lpN62n99yXaZ6X+Zv3JhaJtidD4uxNs\/gNuUq1vNXpi6BZRbtmYZyRmxDFqet38dBLX625IDcJ1sC71kdczV5KGQR2BT2lpLO62+XcuABQJRvXuuUYTlC63PtPt87TVctpLSWCQJ66WnJSLi7LqNmhb7552NLbynpnHxApKcaDjfttzdGGIZaJmgRK9UyQSZebBZ2aNCaSZaSzo6G5WPQhh+QLNrpcDNSb88MPeOEk89YCHVDhI5f0XRwr+2ZDO6H9E6MXms4I6Odtmp1\/T3dRLYaoZEiLXvdXB\/prcui1+2mLaX3+zAFWi4sHafczlP+fktn40hv9VvB1dqsdLk+eaY9HwujGCnk5mhqeXMzEFgLcUwk93tdjq143RQb2d2NCpGtNTflCEsvdkOhh1sdRjD1Uym8uCRE+QUvz3se\/\/wB9z0UYlx93ctoHYFyEQAA49EuM6DquizyHAfZ8ObDwGrY73Tvaz2GLvOJJXZJELyMl+cDX77WX5jy8cehaJRn2URbW2TRYmhEuYgWepf3OF17z1P+zrs4T\/ltiLJkEUDGFRCi\/MLCusXbeOqFBM97OejeP9NyRPWpAHqb215aXImueReWeE\/omzcYd\/V2p\/NOfx8gi+fRu9+sL3BLyOJgUVWPNyDoOvg75B0PZ5Q0OvfdnkmHSO9IVCSfPesz7RXZVu100T1Co1LyI7+k5MSet1vPCqwon5rNUqwp73EAmB3y8jHY57+MG\/V2BL0WRjH7X2ywMelTDwDcTuF4mwLQvf\/t3kdBSdqAgA5+VW62IhDtlW0VyWd0S10WGd0f5t03ASNI6RVpm2xj8jEIqNBhVc9j1bbTzR4zllWX9z7ySwcRAOhgOp9aBtqJP3NZ5cADALd7Vnlm3Cc6\/dTZNqmpSD6Lx1eM03qmV3mPAwCEj6pZofsuZBGA0GFn1t3Zt1u9+frkj47iJ5\/zmuIiWYTdmzUnCXcwU0gHtE5snn7KwdBhzdR7uPDIYTwEc293O+9U5aF8gFrPo1+\/WV+g1vmUbWKw9CLlwNf66pg\/7nvHIxkljcP9t2fSINI7En01cpThYx6kt2uEVvMxbyijoN4\/zkpq2Rsv1Nt\/CFbUcxG6pWWmy\/Xehx9TejvWIlULo5jYs59Pyi8EPV2l2bhoNHGzcdHIx+nWb9YcV6lZwUjYKu9xRu2mTJ9eW49m25i229YLa6fftMtYV\/3u15fln1o7w0i90nZKTWX1lv70cocGwOFd33okhgOhjj0cS+mtSD5DZzQDG38oxHTfhSzausCprZi2b9Yg9eqicbrHtfoC5SLc7pm598yP1dzbFs47SB3KB0i\/cqFfv1lfYMgb\/fDTkwc9iP9odX5gkPTWZZFhQlL37tygOx7eKGms5t9je6aTA9NtexjI+q7\/Gf7qP53FwVzSo+9s08j2HIj7ueDcMULXZdGra6W19CJF0oQXD5Be7SVosY6vvHUs1mJM6S3GaXPCR97aKEZLomxfWlUOPMaBn+K1CuvKW25cNJr6yHKCsZEqdd64UquaLpyWX\/76rq0xstg1ATeLiD4uyv+7ulJ\/s64aacNZ+1hynvIbaa56S1\/1\/UJaLRqrWcHUT9pCpmXyrLX09pu2PvrudXvh8l8\/goDafoWx\/k2x2BgsJZ3GZOd4g40Xkcm1RwusdkvqVaNZM\/e2tfNOLx+g7ucx8Idsg7XPsPSV3noh7vVGjhSEcVXe\/+bXjs33fs5HIxgljdPsubBn0qq5d8HWbTJ21Ns1fBTj9PVk\/U5SeW6djhH61WNXC4YCADpYl+fzE3P552utAsYO68Pvax21IiUT8vK7hTrGqPQ8+aOhIbchvecpf9vw1cMoxiKJ0vybLSWdLbWrZYKADh+dpoPu\/TM1K+i1N08\/5QAIpI\/iXPjoeQwCeid94OsULtPVNV+YjRflrGBcRhYB4J4UshusKP\/XuupqK2HbLA7XzagXHnEABjNVJIvQOCiMLnPbwoE5W7N70RjJIjQP81r4Z5Glasdeb0XyObw78rvWdSxONFw\/OFRK+oNpBZlMdy5fCBDQO0fpIPek9A9zb1s77\/TyAep+Hpmv+\/abPdY+Q9JbepEi+eHiZvo4l8vlvnvks9w8GHTHwxgljdPs+bBnwkR6R8TGleHyHtdKya2mA\/fy7SLW23q4PepFytHjra0On6O2qLdeeLq19blmmlGXRcbx4MlRLpfL5b4QaNPQcht7veYjgXprLYxi1KzQFY2azF96+8jotQmr\/Hpie5mimYWlz4oqKu3zrsXFQKLrNHSHL8wvl8jKY2Y79xb1qFqbBnSnvmllQx7GMB+oFxJeh3ttaysSCj3sXFNrz587+dyjeWlQTPDr31plynuc1SZYMU7ffH8Tvc1t8y5eiK56XPym5YmGeiHhpRg+KqyuJvTW66Y7As9vJyIsZNil8GEFt\/e2lfNOv+fX+Tz691uPC9wOvTOcE0z7El+XGcvAb+ywRknjMB\/2TER6R8S2DGeMMVKONpfYJSG66vGM\/0WdZqwynM+fr7laA7Xr4\/1\/YTW36YDU8jMjDnv1WAuLAXSwrujf3+PyUy8F2e28imuHIdg2aJjCKusDLwZjSe+QRwLR5X9ezopDTvNN8WW5x3dNs+YY5ti69bneISglneTlsZOh57lewrDcpj3TlErv1BqdWe22EXoy9gg9OmpW6Pt2tBGlV9tOpKh7uRrRRuXZMgXc+6+1l6obccAAxvOlUmWRGfIChBtjZ5wwP0zKngmjyZr0DMX0Gp3Z6WY1F9jmHDiIiuTr\/yMZUXorz5Yph4Pxdi\/63jcqh+sLFL30sG0xbwhGd2S221OU0J\/eHs6E3kzMnmkamV6js7YEP8Iw2OiZ3xOkSH42ZOGsYIK8uch+6oWn+\/nLYUtf5vefEt2dJKWkk4S9hBGYWqOzyTv23QtGG6FH54\/y4e5AB30ivYS5Ix+D99KglnD7WBud3RHkfb0zDJFewtyhnXydljVDwuzQw+jsjuhjrEuYeoj0EuYPVNih+75VhEDopqfR2d2ACjv0tMTfhJEh0kuYR8p73D19ISnhdhhgdDZ51OOW8TZhFiHSS5hL6lkB2vGKZMI8MNjobOJU0wHAiPKUROCEkSHSS5hTKik\/nIIhlDD9DDY6mzSqLNJM6JCEvLMLkV7CvIIUyQ+nxx2BQBgSVIwzzIBjo4Qph0gvYY6ZxPF6AsFWiAfPvYBIL2GuQYrkpyxeAk0gTCPD+CQRZgEivYR5B6lXF+O9RJdAmDDNxsXV1HlcE8aASC+BQCAQCBOFSC+BQCAQCBOFSC+BQCAQCBPl\/zj2Lgcr6YguAAAAAElFTkSuQmCC#fixme\" alt=\"\" \/><\/p>\r\n<p class=\"para editable block\">A neutral hydrogen atom has one valence electron. Each hydrogen atom in the molecule shares one pair of bonding electrons and is therefore assigned one electron [0 nonbonding e<sup class=\"superscript\">\u2212<\/sup>\u00a0+\u00a0(2 bonding e<sup class=\"superscript\">\u2212<\/sup>\/2)]. Using Equation 4.4.1 to calculate the formal charge on hydrogen, we obtain:<\/p>\r\n<p style=\"text-align: center\">formalcharge(H)=1\u00a0valence\u00a0e<sup>\u2212<\/sup>\u2212(0\u00a0non\u2212bonding\u00a0e<sup>\u2212\u00a0<\/sup>+\u00a02\u00a0bonding\u00a0e<sup>\u2212<\/sup>\/2)=0<img class=\"aligncenter\" src=\"https:\/\/chem.libretexts.org\/LibreTexts\/Sonoma_State_University\/SSU_Chem_335A\/Material_for_Exam_1\/Unit_2%3A_Polar_Covalent_Bonds%3B_Acids_and_Bases\/denied:data:image\/png;base64,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#fixme\" alt=\"\" \/><\/p>\r\n<p class=\"para editable block\">The hydrogen atoms in ammonia have the same number of electrons as neutral hydrogen atoms, and so their formal charge is also zero. Adding together the formal charges should give us the overall charge on the molecule or ion. In this example, the nitrogen and each hydrogen has a formal charge of zero. When summed the overall charge is zero, which is consistent with the overall charge on the NH<sub class=\"subscript\">3<\/sub> molecule.<\/p>\r\n<p class=\"para editable block\">Typically, the structure with the most charges on the atoms closest to zero is the more stable Lewis structure. In cases where there are positive or negative formal charges on various atoms, stable structures generally have negative formal charges on the more electronegative atoms and positive formal charges on the less electronegative atoms. The next example further demonstrates how to calculate formal charges.<\/p>\r\n\r\n<div>\r\n<div id=\"example\">\r\n<div class=\"textbox examples\">\r\n<h3>Examples<\/h3>\r\n<div id=\"section_1\">\r\n<div>\r\n<div id=\"example\">\r\n<p class=\"para\">Calculate the formal charges on each atom in the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion.<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">Given: <\/strong>chemical species<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">Asked for: <\/strong>formal charges<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">Strategy:<\/strong><\/p>\r\n<p class=\"para\">Identify the number of valence electrons in each atom in the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion. Use the Lewis electron structure of NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> to identify the number of bonding and nonbonding electrons associated with each atom and then use Equation 4.4.1 to calculate the formal charge on each atom.\r\n[reveal-answer q=\"161731\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"161731\"]<\/p>\r\n<p class=\"para\">The Lewis electron structure for the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion is as follows:<\/p>\r\n\r\n<div class=\"informalfigure large medium-height\">\r\n<p class=\"p1\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145255\/67c2f8a9e1f13d7325f739b98bcc30e9.jpg\" alt=\"67c2f8a9e1f13d7325f739b98bcc30e9.jpg\" width=\"550px\" height=\"82px\" \/><\/p>\r\n\r\n<\/div>\r\n<p class=\"para\">The nitrogen atom shares four bonding pairs of electrons, and a neutral nitrogen atom has five valence electrons. Using Equation 4.4.1, the formal charge on the nitrogen atom is therefore<\/p>\r\n<p style=\"text-align: center\">formalcharge(N)=5\u2212(0+82)=0\u200b<\/p>\r\n<p class=\"para\">Each hydrogen atom in has one bonding pair. The formal charge on each hydrogen atom is therefore<\/p>\r\n<p style=\"text-align: center\">formalcharge(H)=1\u2212(0+22)=0\u200b<\/p>\r\n<p class=\"para\">The formal charges on the atoms in the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion are thus<\/p>\r\n<p class=\"para\"><a class=\"thumb\" title=\"5e0f7f069aee8f92ef91dd65654d5a9c.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28106\/5e0f7f069aee8f92ef91dd65654d5a9c.jpg?revision=1\" rel=\"internal\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145258\/5e0f7f069aee8f92ef91dd65654d5a9c.jpg\" alt=\"5e0f7f069aee8f92ef91dd65654d5a9c.jpg\" width=\"550px\" height=\"106px\" \/><\/a><\/p>\r\n<p class=\"para\">Adding together the formal charges on the atoms should give us the total charge on the molecule or ion. In this case, the sum of the formal charges is 0\u00a0+\u00a01\u00a0+\u00a00\u00a0+\u00a00\u00a0+\u00a00\u00a0=\u00a0+1.<\/p>\r\n<p class=\"para\">[\/hidden-answer]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div>\r\n<div id=\"exercise\">\r\n<p class=\"boxtitle\"><span style=\"text-decoration: underline\"><strong>Exercise<\/strong><\/span><\/p>\r\n<p class=\"para\">Write the formal charges on all atoms in BH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">\u2212<\/sup>.\r\n[reveal-answer q=\"476595\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"476595\"]<a class=\"thumb\" title=\"c36560409246c6322bb1d1a06fed7586.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28107\/c36560409246c6322bb1d1a06fed7586.jpg?revision=1\" rel=\"internal\">\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145300\/c36560409246c6322bb1d1a06fed7586.jpg\" alt=\"c36560409246c6322bb1d1a06fed7586.jpg\" width=\"550px\" height=\"106px\" \/><\/a><\/p>\r\n<p class=\"para editable block\">If an atom in a molecule or ion has the number of bonds that is typical for that atom (e.g., four bonds for carbon), its formal charge is zero.<\/p>\r\n<p class=\"para\">[\/hidden-answer]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<h3 class=\"para\">Common bonding patterns in organic structures<\/h3>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<div id=\"section_2\">\r\n\r\nThe methods reviewed above for drawing Lewis structures and determining formal charges on atoms are an essential starting point for a novice organic chemist, and work quite will when dealing with small, simple structures.\u00a0 But as you can imagine, these methods become unreasonably tedious and time-consuming when you start dealing with larger structures.\u00a0 It would be unrealistic, for example, to ask you to draw the Lewis structure below (of one of the four nucleoside building blocks that make up DNA) and determine all formal charges by adding up, on an atom-by-atom basis, the valence electrons.\r\n\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145305\/image045.png\" alt=\"image040.png\" width=\"235px\" height=\"207px\" \/>\r\n\r\nAnd yet, as organic chemists, and especially as organic chemists dealing with biological molecules, you will be expected soon to draw the structure of large molecules such as this on a regular basis.\u00a0 Clearly, you need to develop the ability to quickly and efficiently draw large structures and determine formal charges.\u00a0 Fortunately, this ability is not terribly hard to come by - all it takes is a few shortcuts and some practice at recognizing common bonding patterns.\r\n\r\nLet\u2019s start with carbon, the most important element for organic chemists.\u00a0 Carbon is said to be tetravalent, meaning that it tends to form four bonds.\u00a0 If you look at the simple structures of methane, methanol, ethane, ethene, and ethyne in the figures from the previous section, you should quickly recognize that in each molecule, the carbon atom has four bonds, and a formal charge of zero.\r\n\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145308\/image047.png\" alt=\"image042.png\" width=\"312px\" height=\"115px\" \/>\r\n\r\nThis is a pattern that holds throughout most of the organic molecules we will see, but there are also exceptions.\r\n\r\nIn carbon dioxide, the carbon atom has double bonds to oxygen on both sides (O=C=O).\u00a0 Later on in this chapter and throughout this book we will see examples of organic ions called \u2018carbocations\u2019 and carbanions\u2019, in which a carbon atom bears a positive or negative formal charge, respectively.\u00a0 If a carbon has only three bonds and an unfilled valence shell (in other words, if it does not fulfill the octet rule), it will have a positive formal charge.\r\n\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145310\/image049.png\" alt=\"image044.png\" width=\"567px\" height=\"122px\" \/>\r\n\r\nIf, on the other hand, it has three bonds plus a lone pair of electrons, it will have a formal charge of -1.\u00a0 Another possibility is a carbon with three bonds and a single, unpaired (free radical) electron: in this case, the carbon has a formal charge of zero. (One last possibility is a highly reactive species called a \u2018carbene\u2019, in which a carbon has two bonds and one lone pair of electrons, giving it a formal charge of zero.\u00a0 You may encounter carbenes in more advanced chemistry courses, but they will not be discussed any further in this book).\r\n\r\nYou should certainly use the methods you have learned to check that these formal charges are correct for the examples given above.\u00a0 More importantly, you will need, before you progress much further in your study of organic chemistry, to simply recognize these patterns (and the patterns described below for other atoms) and be able to identify carbons that bear positive and negative formal charges by a quick inspection.\r\n\r\nThe pattern for hydrogens is easy: hydrogen atoms\u00a0 have only one bond, and no formal charge. The exceptions to this rule are the proton, H<sup>+<\/sup>, and the hydride ion, H<sup>-<\/sup>, which is a proton plus two electrons. Because we are concentrating in this book on organic chemistry as applied to living things, however, we will not be seeing \u2018naked\u2019 protons and hydrides as such, because they are too reactive to be present in that form in aqueous solution.\u00a0 Nonetheless, the <em>idea<\/em> of a proton will be very important when we discuss acid-base chemistry, and the <em>idea<\/em> of a hydride ion will become very important much later in the book when we discuss organic oxidation and reduction reactions.\u00a0 As a rule, though, all hydrogen atoms in organic molecules have one bond, and no formal charge.\r\n\r\nLet us next turn to oxygen atoms.\u00a0 Typically, you will see an oxygen bonding in three ways, all of which fulfill the octet rule.\r\n\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145314\/image051.png\" alt=\"image046.png\" width=\"573px\" height=\"115px\" \/>\r\n\r\nIf it has two bonds and two lone pairs, as in water, it will have a formal charge of zero.\u00a0 If it has one bond and three lone pairs, as in hydroxide ion, it will have a formal charge of-1.\u00a0 If it has three bonds and one lone pair, as in hydronium ion, it will have a formal charge of +1.\r\n\r\nWhen we get to our discussion of free radical chemistry in later sections, we will see other possibilities, such as where an oxygen atom has one bond, one lone pair, and one unpaired (free radical) electron, giving it a formal charge of zero.\u00a0 For now, however, concentrate on the three main non-radical examples, as these will account for virtually everything we see until much later.\r\n\r\nNitrogen has two major bonding patterns, both of which fulfill the octet rule:\r\n\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145318\/image053.png\" alt=\"image048.png\" width=\"573px\" height=\"197px\" \/>\r\n\r\nIf a nitrogen has three bonds and a lone pair, it has a formal charge of zero.\u00a0 If it has four bonds (and no lone pair), it has a formal charge of +1.\u00a0 In a fairly uncommon bonding pattern, negatively charged nitrogen has two bonds and two lone pairs.\r\n\r\nTwo third row elements are commonly found in biological organic molecules: sulfur and phosphorus.\u00a0 Although both of these elements have other bonding patterns that are relevant in laboratory chemistry, in a biological context sulfur almost always follows the same bonding\/formal charge pattern as oxygen, while phosphorus is present in the form of phosphate ion (PO<sub>4<\/sub><sup>3-<\/sup>), where it has five bonds (almost always to oxygen), no lone pairs, and a formal charge of zero. Remember that elements in the third row of the periodic table have <em>d<\/em> orbitals in their valence shell as well as <em>s<\/em> and <em>p<\/em> orbitals, and thus are not bound by the octet rule.\r\n\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145323\/image055.png\" alt=\"image050.png\" width=\"108px\" height=\"125px\" \/>\r\n\r\nFinally, the halogens (fluorine, chlorine, bromine, and iodine) are very important in laboratory and medicinal organic chemistry, but less common in naturally occurring organic molecules.\u00a0 Halogens in organic compounds usually are seen with one bond, three lone pairs, and a formal charge of zero. Sometimes, especially in the case of bromine, we will encounter reactive species in which the halogen has two bonds (usually in a three-membered ring), two lone pairs, and a formal charge of +1.\r\n\r\n<img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145328\/image057.png\" alt=\"image052.png\" width=\"260px\" height=\"100px\" \/>\r\n\r\nThese rules, if learned and internalized so that you don\u2019t even need to think about them, will allow you to draw large organic structures, complete with formal charges, quite quickly.\r\n\r\nOnce you have gotten the hang of drawing Lewis structures, it is not always necessary to draw lone pairs on heteroatoms, as you can assume that the proper number of electrons are present around each atom to match the indicated formal charge (or lack thereof).\u00a0 Occasionally, though, lone pairs are drawn if doing so helps to make an explanation more clear.\r\n\r\n<\/div>\r\n<div id=\"section_3\">\r\n<h2 class=\"editable\">Using Formal Charges to Distinguish between Lewis Structures<\/h2>\r\n<p class=\"para editable block\">As an example of how formal charges can be used to determine the most stable Lewis structure for a substance, we can compare two possible structures for CO<sub class=\"subscript\">2<\/sub>. Both structures conform to the rules for Lewis electron structures.<\/p>\r\n\r\n<div class=\"section\">\r\n<div id=\"section_4\">\r\n<h2 class=\"editable\">CO<sub class=\"subscript\">2<\/sub><\/h2>\r\n<p class=\"para editable block\">1. C is less electronegative than O, so it is the central atom.<\/p>\r\n<p class=\"para editable block\">2. C has 4 valence electrons and each O has 6 valence electrons, for a total of 16 valence electrons.<\/p>\r\n<p class=\"para editable block\">3. Placing one electron pair between the C and each O gives O\u2013C\u2013O, with 12 electrons left over.<\/p>\r\n<p class=\"para editable block\">4. Dividing the remaining electrons between the O atoms gives three lone pairs on each atom:<\/p>\r\n\r\n<div class=\"informalfigure large medium-height block\"><a class=\"thumb\" title=\"2e184f83e0554f7763706e62c4cac493.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28108\/2e184f83e0554f7763706e62c4cac493.jpg?revision=1\" rel=\"internal\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145330\/2e184f83e0554f7763706e62c4cac493.jpg\" alt=\"2e184f83e0554f7763706e62c4cac493.jpg\" width=\"550px\" height=\"42px\" \/><\/a><\/div>\r\n<p class=\"para editable block\">This structure has an octet of electrons around each O atom but only 4 electrons around the C atom.<\/p>\r\n<p class=\"para editable block\">5. No electrons are left for the central atom.<\/p>\r\n<p class=\"para editable block\">6. To give the carbon atom an octet of electrons, we can convert two of the lone pairs on the oxygen atoms to bonding electron pairs. There are, however, two ways to do this. We can either take one electron pair from each oxygen to form a symmetrical structure or take both electron pairs from a single oxygen atom to give an asymmetrical structure:<\/p>\r\n\r\n<div class=\"informalfigure large medium-height block\"><a class=\"thumb\" title=\"953bde827ee40a4f9b2f65dc8de4f90a.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28109\/953bde827ee40a4f9b2f65dc8de4f90a.jpg?revision=1\" rel=\"internal\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145332\/953bde827ee40a4f9b2f65dc8de4f90a.jpg\" alt=\"953bde827ee40a4f9b2f65dc8de4f90a.jpg\" width=\"550px\" height=\"55px\" \/><\/a><\/div>\r\n<p class=\"para editable block\">Both Lewis electron structures give all three atoms an octet. How do we decide between these two possibilities? The formal charges for the two Lewis electron structures of CO<sub class=\"subscript\">2<\/sub> are as follows:<\/p>\r\n\r\n<div class=\"informalfigure large medium-height block\"><a class=\"thumb\" title=\"6b2663b9111b53775052ac27c63f60db.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28110\/6b2663b9111b53775052ac27c63f60db.jpg?revision=1\" rel=\"internal\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145346\/6b2663b9111b53775052ac27c63f60db.jpg\" alt=\"6b2663b9111b53775052ac27c63f60db.jpg\" width=\"550px\" height=\"55px\" \/><\/a><\/div>\r\n<p class=\"para editable block\">Both Lewis structures have a net formal charge of zero, but the structure on the right has a +1 charge on the more electronegative atom (O). Thus the symmetrical Lewis structure on the left is predicted to be more stable, and it is, in fact, the structure observed experimentally. Remember, though, that formal charges do <em class=\"emphasis\">not<\/em> represent the actual charges on atoms in a molecule or ion. They are used simply as a bookkeeping method for predicting the most stable Lewis structure for a compound.<\/p>\r\n\r\n<blockquote>\r\n<p class=\"boxtitle\"><strong>Note:<\/strong><\/p>\r\n<p class=\"para\">The Lewis structure with the set of formal charges closest to zero is usually the most stable.<\/p>\r\n<\/blockquote>\r\n&nbsp;\r\n<div class=\"textbox examples\">\r\n<h3>Examples<\/h3>\r\n<p class=\"para\">The thiocyanate ion (SCN<sup class=\"superscript\">\u2212<\/sup>), which is used in printing and as a corrosion inhibitor against acidic gases, has at least two possible Lewis electron structures. Draw two possible structures, assign formal charges on all atoms in both, and decide which is the preferred arrangement of electrons.<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">Given: <\/strong>chemical species<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">Asked for: <\/strong>Lewis electron structures, formal charges, and preferred arrangement<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">Strategy:<\/strong><\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">A<\/strong> Use the step-by-step procedure to write two plausible Lewis electron structures for SCN<sup class=\"superscript\">\u2212<\/sup>.<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">B<\/strong> Calculate the formal charge on each atom.<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">C<\/strong> Predict which structure is preferred based on the formal charge on each atom and its electronegativity relative to the other atoms present.\r\n[reveal-answer q=\"126947\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"126947\"]<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">A<\/strong> Possible Lewis structures for the SCN<sup class=\"superscript\">\u2212<\/sup> ion are as follows:<\/p>\r\n\r\n<div class=\"informalfigure large medium-height\"><a class=\"thumb\" title=\"ab56216b8fdfa8b4be145f90f26bc72e.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28111\/ab56216b8fdfa8b4be145f90f26bc72e.jpg?revision=1\" rel=\"internal\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145348\/ab56216b8fdfa8b4be145f90f26bc72e.jpg\" alt=\"ab56216b8fdfa8b4be145f90f26bc72e.jpg\" width=\"550px\" height=\"64px\" \/><\/a><\/div>\r\n<div class=\"informalfigure large medium-height\">\r\n<div class=\"editIcon\"><\/div>\r\n<p class=\"para\"><strong class=\"emphasis bold\">B<\/strong> We must calculate the formal charges on each atom to identify the more stable structure. If we begin with carbon, we notice that the carbon atom in each of these structures shares four bonding pairs, the number of bonds typical for carbon, so it has a formal charge of zero. Continuing with sulfur, we observe that in (a) the sulfur atom shares one bonding pair and has three lone pairs and has a total of six valence electrons. The formal charge on the sulfur atom is therefore 6\u2212(6+22)=\u22121.5\u2212(4+42)=\u22121 In (c), nitrogen has a formal charge of \u22122.<\/p>\r\n<p class=\"para\"><strong class=\"emphasis bold\">C<\/strong> Which structure is preferred? Structure (b) is preferred because the negative charge is on the more electronegative atom (N), and it has lower formal charges on each atom as compared to structure (c): 0, \u22121 versus +1, \u22122.<\/p>\r\n<p class=\"para\">[\/hidden-answer]<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div>\r\n<div class=\"textbox examples\">\r\n<h3>Examples<\/h3>\r\n<div>\r\n<p class=\"para\">Salts containing the fulminate ion (CNO<sup class=\"superscript\">\u2212<\/sup>) are used in explosive detonators. Draw three Lewis electron structures for CNO<sup class=\"superscript\">\u2212<\/sup> and use formal charges to predict which is more stable. (Note: N is the central atom.)\r\n[reveal-answer q=\"574429\"]Show Answer[\/reveal-answer]\r\n[hidden-answer a=\"574429\"]<\/p>\r\n\r\n<div class=\"informalfigure large medium-height\"><a class=\"thumb\" title=\"b8461925b8631574db7a41c2b7a2f0ac.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28112\/b8461925b8631574db7a41c2b7a2f0ac.jpg?revision=1\" rel=\"internal\"><img class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145350\/b8461925b8631574db7a41c2b7a2f0ac.jpg\" alt=\"b8461925b8631574db7a41c2b7a2f0ac.jpg\" width=\"550px\" height=\"69px\" \/><\/a><\/div>\r\n<p class=\"para\">The second structure is predicted to be more stable.<\/p>\r\n\r\n<\/div>\r\n<p class=\"para\">[\/hidden-answer]<\/p>\r\n\r\n<\/div>\r\n&nbsp;\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<div id=\"section_5\">\r\n<h3 class=\"editable\">Contributors<\/h3>\r\n<ul>\r\n \t<li><a class=\"external\" title=\"http:\/\/science.athabascau.ca\/staff-pages\/dietmark\" href=\"http:\/\/science.athabascau.ca\/staff-pages\/dietmark\" target=\"_blank\" rel=\"external nofollow noopener\">Dr. Dietmar Kennepohl<\/a> FCIC (Professor of Chemistry, <a class=\"external\" title=\"http:\/\/www.athabascau.ca\/\" href=\"http:\/\/www.athabascau.ca\/\" target=\"_blank\" rel=\"external nofollow noopener\">Athabasca University<\/a>)<\/li>\r\n \t<li>Prof. Steven Farmer (<a class=\"external\" title=\"http:\/\/www.sonoma.edu\" href=\"http:\/\/www.sonoma.edu\" target=\"_blank\" rel=\"external nofollow noopener\">Sonoma State University<\/a>)<\/li>\r\n \t<li>William Reusch, Professor Emeritus (<a class=\"external\" title=\"http:\/\/www.msu.edu\/\" href=\"http:\/\/www.msu.edu\/\" target=\"_blank\" rel=\"external nofollow noopener\">Michigan State U.<\/a>), <a class=\"external\" title=\"http:\/\/www.cem.msu.edu\/~reusch\/VirtualText\/intro1.htm\" href=\"http:\/\/www.cem.msu.edu\/%7Ereusch\/VirtualText\/intro1.htm\" target=\"_blank\" rel=\"external nofollow noopener\">Virtual Textbook of\u00a0Organic\u00a0Chemistry<\/a><\/li>\r\n \t<li><a title=\"Organic_Chemistry_With_a_Biological_Emphasis\" href=\"https:\/\/chem.libretexts.org\/Textbook_Maps\/Organic_Chemistry_Textbook_Maps\/Map%3A_Organic_Chemistry_with_a_Biological_Emphasis_(Soderberg)\" rel=\"internal\">Organic Chemistry With a Biological Emphasis <\/a>by\u00a0<a class=\"external\" title=\"http:\/\/facultypages.morris.umn.edu\/~soderbt\/\" href=\"http:\/\/facultypages.morris.umn.edu\/%7Esoderbt\/\" target=\"_blank\" rel=\"external nofollow noopener\">Tim Soderberg<\/a>\u00a0(University of Minnesota, Morris)<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<\/div>","rendered":"<div class=\"elm-header\"><\/div>\n<div id=\"elm-main-content\" class=\"elm-content-container\">\n<div id=\"mt-toc-container\" class=\"bc-aside aside\">\n<div class=\"textbox learning-objectives\">\n<h3>Objectives<\/h3>\n<div>\n<div id=\"skills\">\n<p>After completing this section, you should be able to<\/p>\n<ol>\n<li>determine which atoms, if any, of a given simple compound (e.g., HNO<sub>3<\/sub>, CH<sub>2<\/sub>=N=N, CH<sub>3<\/sub>-NC) carry formal charges, and apply the principles used to more complex examples. [The Lewis structure, Kekul\u00e9 structure or molecular formula would normally be provided.]<\/li>\n<li>draw the Lewis structure, the Kekul\u00e9 structure, or both, of a compound of known molecular formula in which certain atoms possess a formal charge<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Key Terms<\/h3>\n<div>\n<div>\n<p>Make certain that you can define, and use in context, each of the key terms listed below.<\/p>\n<ul>\n<li>dipolar<\/li>\n<li>formal charge<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div>\n<div id=\"note\">\n<div class=\"textbox\">\n<p class=\"boxtitle\"><strong>Study Notes<\/strong><\/p>\n<p>Too much emphasis can easily be placed on the concept of formal charge, and the mathematical approach used in the textbook is hard to justify. In this course, you will certainly need to be able to recognize whether a given species carries a charge (i.e., is an ion), but you will not often encounter dipolar molecules, such as the textbook example nitromethane.<\/p>\n<\/div>\n<\/div>\n<div id=\"section_1\">\n<h3 class=\"editable\">Formal Charges<\/h3>\n<p>It is sometimes possible to write more than one Lewis structure for a substance that does not violate the octet rule, as we saw for CH<sub class=\"subscript\">2<\/sub>O, but not every Lewis structure may be equally reasonable. In these situations, we can choose the most stable Lewis structure by considering the <a class=\"glossterm\">formal <\/a><a class=\"glossterm\">charge<\/a> on the atoms, which is the difference between the number of valence electrons in the free atom and the number assigned to it in the Lewis electron structure. The formal charge is a way of computing the charge distribution within a Lewis structure; the sum of the formal charges on the atoms within a molecule or an ion must equal the overall charge on the molecule or ion. A formal charge does <em class=\"emphasis\">not<\/em> represent a true charge on an atom in a covalent bond but is simply used to predict the most likely structure when a compound has more than one valid Lewis structure.<\/p>\n<p>To calculate formal charges, we assign electrons in the molecule to individual atoms according to these rules:<\/p>\n<ul class=\"itemizedlist editable block\">\n<li>Nonbonding electrons are assigned to the atom on which they are located.<\/li>\n<li>Bonding electrons are divided equally between the bonded atoms.<\/li>\n<\/ul>\n<p>For each atom, we then compute a formal charge:<\/p>\n<p style=\"text-align: center\"><strong><img decoding=\"async\" src=\"https:\/\/chem.libretexts.org\/LibreTexts\/Sonoma_State_University\/SSU_Chem_335A\/Material_for_Exam_1\/Unit_2%3A_Polar_Covalent_Bonds%3B_Acids_and_Bases\/denied:data:image\/png;base64,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#fixme\" alt=\"\" \/>formal\u00a0charge\u00a0=\u00a0valence\u00a0e<sup>\u2212\u00a0<\/sup>\u2212(free\u00a0atom)(non\u2212bonding\u00a0e<sup>\u2212\u00a0<\/sup>+\u00a0bonding\u00a0e<sup>&#8211;<\/sup><span style=\"font-size: 13.3333px\">\/2<\/span>)<\/strong><\/p>\n<p class=\"para editable block\">To illustrate this method, let\u2019s calculate the formal charge on the atoms in ammonia (NH<sub class=\"subscript\">3<\/sub>) whose Lewis electron structure is as follows:<\/p>\n<div class=\"informalfigure large block\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145254\/768e2d063688200c5482e54c7905ab81.jpg\" alt=\"768e2d063688200c5482e54c7905ab81.jpg\" width=\"550px\" height=\"88px\" \/><\/div>\n<p>A neutral nitrogen atom has five valence electrons (it is in group 15). From its Lewis electron structure, the nitrogen atom in ammonia has one lone pair and shares three bonding pairs with hydrogen atoms, so nitrogen itself is assigned a total of five electrons [2 nonbonding e<sup class=\"superscript\">\u2212<\/sup>\u00a0+\u00a0(6 bonding e<sup class=\"superscript\">\u2212<\/sup>\/2)]. Substituting into the formula, we obtain<\/p>\n<p style=\"text-align: center\">formalcharge(N)=5\u00a0valence\u00a0e<sup>\u2212<\/sup>\u2212(2\u00a0non\u2212bonding\u00a0e<sup>\u2212<\/sup>\u00a0+\u00a06\u00a0bonding\u00a0e<sup>\u2212<\/sup>\/2)=0<img decoding=\"async\" src=\"https:\/\/chem.libretexts.org\/LibreTexts\/Sonoma_State_University\/SSU_Chem_335A\/Material_for_Exam_1\/Unit_2%3A_Polar_Covalent_Bonds%3B_Acids_and_Bases\/denied:data:image\/png;base64,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#fixme\" alt=\"\" \/><\/p>\n<p class=\"para editable block\">A neutral hydrogen atom has one valence electron. Each hydrogen atom in the molecule shares one pair of bonding electrons and is therefore assigned one electron [0 nonbonding e<sup class=\"superscript\">\u2212<\/sup>\u00a0+\u00a0(2 bonding e<sup class=\"superscript\">\u2212<\/sup>\/2)]. Using Equation 4.4.1 to calculate the formal charge on hydrogen, we obtain:<\/p>\n<p style=\"text-align: center\">formalcharge(H)=1\u00a0valence\u00a0e<sup>\u2212<\/sup>\u2212(0\u00a0non\u2212bonding\u00a0e<sup>\u2212\u00a0<\/sup>+\u00a02\u00a0bonding\u00a0e<sup>\u2212<\/sup>\/2)=0<img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/chem.libretexts.org\/LibreTexts\/Sonoma_State_University\/SSU_Chem_335A\/Material_for_Exam_1\/Unit_2%3A_Polar_Covalent_Bonds%3B_Acids_and_Bases\/denied:data:image\/png;base64,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#fixme\" alt=\"\" \/><\/p>\n<p class=\"para editable block\">The hydrogen atoms in ammonia have the same number of electrons as neutral hydrogen atoms, and so their formal charge is also zero. Adding together the formal charges should give us the overall charge on the molecule or ion. In this example, the nitrogen and each hydrogen has a formal charge of zero. When summed the overall charge is zero, which is consistent with the overall charge on the NH<sub class=\"subscript\">3<\/sub> molecule.<\/p>\n<p class=\"para editable block\">Typically, the structure with the most charges on the atoms closest to zero is the more stable Lewis structure. In cases where there are positive or negative formal charges on various atoms, stable structures generally have negative formal charges on the more electronegative atoms and positive formal charges on the less electronegative atoms. The next example further demonstrates how to calculate formal charges.<\/p>\n<div>\n<div id=\"example\">\n<div class=\"textbox examples\">\n<h3>Examples<\/h3>\n<div id=\"section_1\">\n<div>\n<div id=\"example\">\n<p class=\"para\">Calculate the formal charges on each atom in the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion.<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">Given: <\/strong>chemical species<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">Asked for: <\/strong>formal charges<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">Strategy:<\/strong><\/p>\n<p class=\"para\">Identify the number of valence electrons in each atom in the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion. Use the Lewis electron structure of NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> to identify the number of bonding and nonbonding electrons associated with each atom and then use Equation 4.4.1 to calculate the formal charge on each atom.<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q161731\">Show Answer<\/span><\/p>\n<div id=\"q161731\" class=\"hidden-answer\" style=\"display: none\">\n<p class=\"para\">The Lewis electron structure for the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion is as follows:<\/p>\n<div class=\"informalfigure large medium-height\">\n<p class=\"p1\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145255\/67c2f8a9e1f13d7325f739b98bcc30e9.jpg\" alt=\"67c2f8a9e1f13d7325f739b98bcc30e9.jpg\" width=\"550px\" height=\"82px\" \/><\/p>\n<\/div>\n<p class=\"para\">The nitrogen atom shares four bonding pairs of electrons, and a neutral nitrogen atom has five valence electrons. Using Equation 4.4.1, the formal charge on the nitrogen atom is therefore<\/p>\n<p style=\"text-align: center\">formalcharge(N)=5\u2212(0+82)=0\u200b<\/p>\n<p class=\"para\">Each hydrogen atom in has one bonding pair. The formal charge on each hydrogen atom is therefore<\/p>\n<p style=\"text-align: center\">formalcharge(H)=1\u2212(0+22)=0\u200b<\/p>\n<p class=\"para\">The formal charges on the atoms in the NH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">+<\/sup> ion are thus<\/p>\n<p class=\"para\"><a class=\"thumb\" title=\"5e0f7f069aee8f92ef91dd65654d5a9c.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28106\/5e0f7f069aee8f92ef91dd65654d5a9c.jpg?revision=1\" rel=\"internal\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145258\/5e0f7f069aee8f92ef91dd65654d5a9c.jpg\" alt=\"5e0f7f069aee8f92ef91dd65654d5a9c.jpg\" width=\"550px\" height=\"106px\" \/><\/a><\/p>\n<p class=\"para\">Adding together the formal charges on the atoms should give us the total charge on the molecule or ion. In this case, the sum of the formal charges is 0\u00a0+\u00a01\u00a0+\u00a00\u00a0+\u00a00\u00a0+\u00a00\u00a0=\u00a0+1.<\/p>\n<p class=\"para\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div>\n<div id=\"exercise\">\n<p class=\"boxtitle\"><span style=\"text-decoration: underline\"><strong>Exercise<\/strong><\/span><\/p>\n<p class=\"para\">Write the formal charges on all atoms in BH<sub class=\"subscript\">4<\/sub><sup class=\"superscript\">\u2212<\/sup>.<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q476595\">Show Answer<\/span><\/p>\n<div id=\"q476595\" class=\"hidden-answer\" style=\"display: none\"><a class=\"thumb\" title=\"c36560409246c6322bb1d1a06fed7586.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28107\/c36560409246c6322bb1d1a06fed7586.jpg?revision=1\" rel=\"internal\"><br \/>\n<img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145300\/c36560409246c6322bb1d1a06fed7586.jpg\" alt=\"c36560409246c6322bb1d1a06fed7586.jpg\" width=\"550px\" height=\"106px\" \/><\/a><\/p>\n<p class=\"para editable block\">If an atom in a molecule or ion has the number of bonds that is typical for that atom (e.g., four bonds for carbon), its formal charge is zero.<\/p>\n<p class=\"para\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<h3 class=\"para\">Common bonding patterns in organic structures<\/h3>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"section_2\">\n<p>The methods reviewed above for drawing Lewis structures and determining formal charges on atoms are an essential starting point for a novice organic chemist, and work quite will when dealing with small, simple structures.\u00a0 But as you can imagine, these methods become unreasonably tedious and time-consuming when you start dealing with larger structures.\u00a0 It would be unrealistic, for example, to ask you to draw the Lewis structure below (of one of the four nucleoside building blocks that make up DNA) and determine all formal charges by adding up, on an atom-by-atom basis, the valence electrons.<\/p>\n<p><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145305\/image045.png\" alt=\"image040.png\" width=\"235px\" height=\"207px\" \/><\/p>\n<p>And yet, as organic chemists, and especially as organic chemists dealing with biological molecules, you will be expected soon to draw the structure of large molecules such as this on a regular basis.\u00a0 Clearly, you need to develop the ability to quickly and efficiently draw large structures and determine formal charges.\u00a0 Fortunately, this ability is not terribly hard to come by &#8211; all it takes is a few shortcuts and some practice at recognizing common bonding patterns.<\/p>\n<p>Let\u2019s start with carbon, the most important element for organic chemists.\u00a0 Carbon is said to be tetravalent, meaning that it tends to form four bonds.\u00a0 If you look at the simple structures of methane, methanol, ethane, ethene, and ethyne in the figures from the previous section, you should quickly recognize that in each molecule, the carbon atom has four bonds, and a formal charge of zero.<\/p>\n<p><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145308\/image047.png\" alt=\"image042.png\" width=\"312px\" height=\"115px\" \/><\/p>\n<p>This is a pattern that holds throughout most of the organic molecules we will see, but there are also exceptions.<\/p>\n<p>In carbon dioxide, the carbon atom has double bonds to oxygen on both sides (O=C=O).\u00a0 Later on in this chapter and throughout this book we will see examples of organic ions called \u2018carbocations\u2019 and carbanions\u2019, in which a carbon atom bears a positive or negative formal charge, respectively.\u00a0 If a carbon has only three bonds and an unfilled valence shell (in other words, if it does not fulfill the octet rule), it will have a positive formal charge.<\/p>\n<p><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145310\/image049.png\" alt=\"image044.png\" width=\"567px\" height=\"122px\" \/><\/p>\n<p>If, on the other hand, it has three bonds plus a lone pair of electrons, it will have a formal charge of -1.\u00a0 Another possibility is a carbon with three bonds and a single, unpaired (free radical) electron: in this case, the carbon has a formal charge of zero. (One last possibility is a highly reactive species called a \u2018carbene\u2019, in which a carbon has two bonds and one lone pair of electrons, giving it a formal charge of zero.\u00a0 You may encounter carbenes in more advanced chemistry courses, but they will not be discussed any further in this book).<\/p>\n<p>You should certainly use the methods you have learned to check that these formal charges are correct for the examples given above.\u00a0 More importantly, you will need, before you progress much further in your study of organic chemistry, to simply recognize these patterns (and the patterns described below for other atoms) and be able to identify carbons that bear positive and negative formal charges by a quick inspection.<\/p>\n<p>The pattern for hydrogens is easy: hydrogen atoms\u00a0 have only one bond, and no formal charge. The exceptions to this rule are the proton, H<sup>+<\/sup>, and the hydride ion, H<sup>&#8211;<\/sup>, which is a proton plus two electrons. Because we are concentrating in this book on organic chemistry as applied to living things, however, we will not be seeing \u2018naked\u2019 protons and hydrides as such, because they are too reactive to be present in that form in aqueous solution.\u00a0 Nonetheless, the <em>idea<\/em> of a proton will be very important when we discuss acid-base chemistry, and the <em>idea<\/em> of a hydride ion will become very important much later in the book when we discuss organic oxidation and reduction reactions.\u00a0 As a rule, though, all hydrogen atoms in organic molecules have one bond, and no formal charge.<\/p>\n<p>Let us next turn to oxygen atoms.\u00a0 Typically, you will see an oxygen bonding in three ways, all of which fulfill the octet rule.<\/p>\n<p><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145314\/image051.png\" alt=\"image046.png\" width=\"573px\" height=\"115px\" \/><\/p>\n<p>If it has two bonds and two lone pairs, as in water, it will have a formal charge of zero.\u00a0 If it has one bond and three lone pairs, as in hydroxide ion, it will have a formal charge of-1.\u00a0 If it has three bonds and one lone pair, as in hydronium ion, it will have a formal charge of +1.<\/p>\n<p>When we get to our discussion of free radical chemistry in later sections, we will see other possibilities, such as where an oxygen atom has one bond, one lone pair, and one unpaired (free radical) electron, giving it a formal charge of zero.\u00a0 For now, however, concentrate on the three main non-radical examples, as these will account for virtually everything we see until much later.<\/p>\n<p>Nitrogen has two major bonding patterns, both of which fulfill the octet rule:<\/p>\n<p><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145318\/image053.png\" alt=\"image048.png\" width=\"573px\" height=\"197px\" \/><\/p>\n<p>If a nitrogen has three bonds and a lone pair, it has a formal charge of zero.\u00a0 If it has four bonds (and no lone pair), it has a formal charge of +1.\u00a0 In a fairly uncommon bonding pattern, negatively charged nitrogen has two bonds and two lone pairs.<\/p>\n<p>Two third row elements are commonly found in biological organic molecules: sulfur and phosphorus.\u00a0 Although both of these elements have other bonding patterns that are relevant in laboratory chemistry, in a biological context sulfur almost always follows the same bonding\/formal charge pattern as oxygen, while phosphorus is present in the form of phosphate ion (PO<sub>4<\/sub><sup>3-<\/sup>), where it has five bonds (almost always to oxygen), no lone pairs, and a formal charge of zero. Remember that elements in the third row of the periodic table have <em>d<\/em> orbitals in their valence shell as well as <em>s<\/em> and <em>p<\/em> orbitals, and thus are not bound by the octet rule.<\/p>\n<p><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145323\/image055.png\" alt=\"image050.png\" width=\"108px\" height=\"125px\" \/><\/p>\n<p>Finally, the halogens (fluorine, chlorine, bromine, and iodine) are very important in laboratory and medicinal organic chemistry, but less common in naturally occurring organic molecules.\u00a0 Halogens in organic compounds usually are seen with one bond, three lone pairs, and a formal charge of zero. Sometimes, especially in the case of bromine, we will encounter reactive species in which the halogen has two bonds (usually in a three-membered ring), two lone pairs, and a formal charge of +1.<\/p>\n<p><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145328\/image057.png\" alt=\"image052.png\" width=\"260px\" height=\"100px\" \/><\/p>\n<p>These rules, if learned and internalized so that you don\u2019t even need to think about them, will allow you to draw large organic structures, complete with formal charges, quite quickly.<\/p>\n<p>Once you have gotten the hang of drawing Lewis structures, it is not always necessary to draw lone pairs on heteroatoms, as you can assume that the proper number of electrons are present around each atom to match the indicated formal charge (or lack thereof).\u00a0 Occasionally, though, lone pairs are drawn if doing so helps to make an explanation more clear.<\/p>\n<\/div>\n<div id=\"section_3\">\n<h2 class=\"editable\">Using Formal Charges to Distinguish between Lewis Structures<\/h2>\n<p class=\"para editable block\">As an example of how formal charges can be used to determine the most stable Lewis structure for a substance, we can compare two possible structures for CO<sub class=\"subscript\">2<\/sub>. Both structures conform to the rules for Lewis electron structures.<\/p>\n<div class=\"section\">\n<div id=\"section_4\">\n<h2 class=\"editable\">CO<sub class=\"subscript\">2<\/sub><\/h2>\n<p class=\"para editable block\">1. C is less electronegative than O, so it is the central atom.<\/p>\n<p class=\"para editable block\">2. C has 4 valence electrons and each O has 6 valence electrons, for a total of 16 valence electrons.<\/p>\n<p class=\"para editable block\">3. Placing one electron pair between the C and each O gives O\u2013C\u2013O, with 12 electrons left over.<\/p>\n<p class=\"para editable block\">4. Dividing the remaining electrons between the O atoms gives three lone pairs on each atom:<\/p>\n<div class=\"informalfigure large medium-height block\"><a class=\"thumb\" title=\"2e184f83e0554f7763706e62c4cac493.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28108\/2e184f83e0554f7763706e62c4cac493.jpg?revision=1\" rel=\"internal\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145330\/2e184f83e0554f7763706e62c4cac493.jpg\" alt=\"2e184f83e0554f7763706e62c4cac493.jpg\" width=\"550px\" height=\"42px\" \/><\/a><\/div>\n<p class=\"para editable block\">This structure has an octet of electrons around each O atom but only 4 electrons around the C atom.<\/p>\n<p class=\"para editable block\">5. No electrons are left for the central atom.<\/p>\n<p class=\"para editable block\">6. To give the carbon atom an octet of electrons, we can convert two of the lone pairs on the oxygen atoms to bonding electron pairs. There are, however, two ways to do this. We can either take one electron pair from each oxygen to form a symmetrical structure or take both electron pairs from a single oxygen atom to give an asymmetrical structure:<\/p>\n<div class=\"informalfigure large medium-height block\"><a class=\"thumb\" title=\"953bde827ee40a4f9b2f65dc8de4f90a.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28109\/953bde827ee40a4f9b2f65dc8de4f90a.jpg?revision=1\" rel=\"internal\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145332\/953bde827ee40a4f9b2f65dc8de4f90a.jpg\" alt=\"953bde827ee40a4f9b2f65dc8de4f90a.jpg\" width=\"550px\" height=\"55px\" \/><\/a><\/div>\n<p class=\"para editable block\">Both Lewis electron structures give all three atoms an octet. How do we decide between these two possibilities? The formal charges for the two Lewis electron structures of CO<sub class=\"subscript\">2<\/sub> are as follows:<\/p>\n<div class=\"informalfigure large medium-height block\"><a class=\"thumb\" title=\"6b2663b9111b53775052ac27c63f60db.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28110\/6b2663b9111b53775052ac27c63f60db.jpg?revision=1\" rel=\"internal\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145346\/6b2663b9111b53775052ac27c63f60db.jpg\" alt=\"6b2663b9111b53775052ac27c63f60db.jpg\" width=\"550px\" height=\"55px\" \/><\/a><\/div>\n<p class=\"para editable block\">Both Lewis structures have a net formal charge of zero, but the structure on the right has a +1 charge on the more electronegative atom (O). Thus the symmetrical Lewis structure on the left is predicted to be more stable, and it is, in fact, the structure observed experimentally. Remember, though, that formal charges do <em class=\"emphasis\">not<\/em> represent the actual charges on atoms in a molecule or ion. They are used simply as a bookkeeping method for predicting the most stable Lewis structure for a compound.<\/p>\n<blockquote>\n<p class=\"boxtitle\"><strong>Note:<\/strong><\/p>\n<p class=\"para\">The Lewis structure with the set of formal charges closest to zero is usually the most stable.<\/p>\n<\/blockquote>\n<p>&nbsp;<\/p>\n<div class=\"textbox examples\">\n<h3>Examples<\/h3>\n<p class=\"para\">The thiocyanate ion (SCN<sup class=\"superscript\">\u2212<\/sup>), which is used in printing and as a corrosion inhibitor against acidic gases, has at least two possible Lewis electron structures. Draw two possible structures, assign formal charges on all atoms in both, and decide which is the preferred arrangement of electrons.<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">Given: <\/strong>chemical species<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">Asked for: <\/strong>Lewis electron structures, formal charges, and preferred arrangement<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">Strategy:<\/strong><\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">A<\/strong> Use the step-by-step procedure to write two plausible Lewis electron structures for SCN<sup class=\"superscript\">\u2212<\/sup>.<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">B<\/strong> Calculate the formal charge on each atom.<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">C<\/strong> Predict which structure is preferred based on the formal charge on each atom and its electronegativity relative to the other atoms present.<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q126947\">Show Answer<\/span><\/p>\n<div id=\"q126947\" class=\"hidden-answer\" style=\"display: none\">\n<p class=\"para\"><strong class=\"emphasis bold\">A<\/strong> Possible Lewis structures for the SCN<sup class=\"superscript\">\u2212<\/sup> ion are as follows:<\/p>\n<div class=\"informalfigure large medium-height\"><a class=\"thumb\" title=\"ab56216b8fdfa8b4be145f90f26bc72e.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28111\/ab56216b8fdfa8b4be145f90f26bc72e.jpg?revision=1\" rel=\"internal\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145348\/ab56216b8fdfa8b4be145f90f26bc72e.jpg\" alt=\"ab56216b8fdfa8b4be145f90f26bc72e.jpg\" width=\"550px\" height=\"64px\" \/><\/a><\/div>\n<div class=\"informalfigure large medium-height\">\n<div class=\"editIcon\"><\/div>\n<p class=\"para\"><strong class=\"emphasis bold\">B<\/strong> We must calculate the formal charges on each atom to identify the more stable structure. If we begin with carbon, we notice that the carbon atom in each of these structures shares four bonding pairs, the number of bonds typical for carbon, so it has a formal charge of zero. Continuing with sulfur, we observe that in (a) the sulfur atom shares one bonding pair and has three lone pairs and has a total of six valence electrons. The formal charge on the sulfur atom is therefore 6\u2212(6+22)=\u22121.5\u2212(4+42)=\u22121 In (c), nitrogen has a formal charge of \u22122.<\/p>\n<p class=\"para\"><strong class=\"emphasis bold\">C<\/strong> Which structure is preferred? Structure (b) is preferred because the negative charge is on the more electronegative atom (N), and it has lower formal charges on each atom as compared to structure (c): 0, \u22121 versus +1, \u22122.<\/p>\n<p class=\"para\"><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div>\n<div class=\"textbox examples\">\n<h3>Examples<\/h3>\n<div>\n<p class=\"para\">Salts containing the fulminate ion (CNO<sup class=\"superscript\">\u2212<\/sup>) are used in explosive detonators. Draw three Lewis electron structures for CNO<sup class=\"superscript\">\u2212<\/sup> and use formal charges to predict which is more stable. (Note: N is the central atom.)<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q574429\">Show Answer<\/span><\/p>\n<div id=\"q574429\" class=\"hidden-answer\" style=\"display: none\">\n<div class=\"informalfigure large medium-height\"><a class=\"thumb\" title=\"b8461925b8631574db7a41c2b7a2f0ac.jpg\" href=\"https:\/\/chem.libretexts.org\/@api\/deki\/files\/28112\/b8461925b8631574db7a41c2b7a2f0ac.jpg?revision=1\" rel=\"internal\"><img decoding=\"async\" class=\"internal default aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images\/wp-content\/uploads\/sites\/1518\/2017\/10\/04145350\/b8461925b8631574db7a41c2b7a2f0ac.jpg\" alt=\"b8461925b8631574db7a41c2b7a2f0ac.jpg\" width=\"550px\" height=\"69px\" \/><\/a><\/div>\n<p class=\"para\">The second structure is predicted to be more stable.<\/p>\n<\/div>\n<p class=\"para\"><\/div>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<div id=\"section_5\">\n<h3 class=\"editable\">Contributors<\/h3>\n<ul>\n<li><a class=\"external\" title=\"http:\/\/science.athabascau.ca\/staff-pages\/dietmark\" href=\"http:\/\/science.athabascau.ca\/staff-pages\/dietmark\" target=\"_blank\" rel=\"external nofollow noopener\">Dr. Dietmar Kennepohl<\/a> FCIC (Professor of Chemistry, <a class=\"external\" title=\"http:\/\/www.athabascau.ca\/\" href=\"http:\/\/www.athabascau.ca\/\" target=\"_blank\" rel=\"external nofollow noopener\">Athabasca University<\/a>)<\/li>\n<li>Prof. Steven Farmer (<a class=\"external\" title=\"http:\/\/www.sonoma.edu\" href=\"http:\/\/www.sonoma.edu\" target=\"_blank\" rel=\"external nofollow noopener\">Sonoma State University<\/a>)<\/li>\n<li>William Reusch, Professor Emeritus (<a class=\"external\" title=\"http:\/\/www.msu.edu\/\" href=\"http:\/\/www.msu.edu\/\" target=\"_blank\" rel=\"external nofollow noopener\">Michigan State U.<\/a>), <a class=\"external\" title=\"http:\/\/www.cem.msu.edu\/~reusch\/VirtualText\/intro1.htm\" href=\"http:\/\/www.cem.msu.edu\/%7Ereusch\/VirtualText\/intro1.htm\" target=\"_blank\" rel=\"external nofollow noopener\">Virtual Textbook of\u00a0Organic\u00a0Chemistry<\/a><\/li>\n<li><a title=\"Organic_Chemistry_With_a_Biological_Emphasis\" href=\"https:\/\/chem.libretexts.org\/Textbook_Maps\/Organic_Chemistry_Textbook_Maps\/Map%3A_Organic_Chemistry_with_a_Biological_Emphasis_(Soderberg)\" rel=\"internal\">Organic Chemistry With a Biological Emphasis <\/a>by\u00a0<a class=\"external\" title=\"http:\/\/facultypages.morris.umn.edu\/~soderbt\/\" href=\"http:\/\/facultypages.morris.umn.edu\/%7Esoderbt\/\" target=\"_blank\" rel=\"external nofollow noopener\">Tim Soderberg<\/a>\u00a0(University of Minnesota, Morris)<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"author":311,"menu_order":6,"template":"","meta":{"_candela_citation":"[]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-174","chapter","type-chapter","status-publish","hentry"],"part":76,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/pressbooks\/v2\/chapters\/174","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/wp\/v2\/users\/311"}],"version-history":[{"count":12,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/pressbooks\/v2\/chapters\/174\/revisions"}],"predecessor-version":[{"id":2230,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/pressbooks\/v2\/chapters\/174\/revisions\/2230"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/pressbooks\/v2\/parts\/76"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/pressbooks\/v2\/chapters\/174\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/wp\/v2\/media?parent=174"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/pressbooks\/v2\/chapter-type?post=174"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/wp\/v2\/contributor?post=174"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/suny-mcc-organicchemistry\/wp-json\/wp\/v2\/license?post=174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}