{"id":214800,"date":"2025-05-15T12:51:41","date_gmt":"2025-05-15T12:51:41","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=214800"},"modified":"2025-05-15T13:21:35","modified_gmt":"2025-05-15T13:21:35","slug":"draw-the-lewis-structure-for-nco-the-oyanate-anion-and-calcle-charges-which-statement-is-true","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/15\/draw-the-lewis-structure-for-nco-the-oyanate-anion-and-calcle-charges-which-statement-is-true\/","title":{"rendered":"Draw the Lewis structure for NCo, the oyanate anion, and calcle charges"},"content":{"rendered":"\n<p>Draw the Lewis sructure for NCo, the oyanate anion, and calcle charges. Which statement is true:<\/p>\n\n\n\n<p>A. In the best Lewis structure the formal charge of the onygrn is<br>B. In the best Lewis structure the formal charge of the osy gen is<br>C. In the best Lewis structure the formal charge of the carbon is<br>D. In the best Lewis structure the formal charge of the nitrogen is -1<br>E. In the best Lewis structure the formal charge of the nitrogen is -2<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>To determine the correct Lewis structure of the <strong>cyanate ion (NCO\u207b)<\/strong> and the associated <strong>formal charges<\/strong>, we must follow a systematic approach:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 1: Count the Total Valence Electrons<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Nitrogen (N): 5 valence electrons<\/li>\n\n\n\n<li>Carbon (C): 4 valence electrons<\/li>\n\n\n\n<li>Oxygen (O): 6 valence electrons<\/li>\n\n\n\n<li>Cyanate ion has a <strong>-1 charge<\/strong>, so add <strong>1 more electron<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>Total<\/strong> = 5 (N) + 4 (C) + 6 (O) + 1 = <strong>16 valence electrons<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 2: Construct Possible Lewis Structures<\/strong><\/h3>\n\n\n\n<p>We try different bonding arrangements with C in the center (as is typical), and we consider:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>N\u2013C\u2261O<\/strong><\/li>\n\n\n\n<li><strong>N\u2261C\u2013O<\/strong><\/li>\n\n\n\n<li><strong>N=C=O<\/strong><\/li>\n<\/ul>\n\n\n\n<p>After testing resonance and evaluating formal charges, the most stable Lewis structure is:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>N\u207b\u2013C\u2261O\u207a<\/strong><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>  :N\u207b:\u2014C\u2261O\u207a\n<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Nitrogen: 1 lone pair, 1 single bond \u2192 <strong>6 valence electrons<\/strong><\/li>\n\n\n\n<li>Carbon: 1 single bond, 1 triple bond \u2192 <strong>4 valence electrons<\/strong><\/li>\n\n\n\n<li>Oxygen: 2 lone pairs, 1 triple bond \u2192 <strong>6 valence electrons<\/strong><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 3: Calculate Formal Charges<\/strong><\/h3>\n\n\n\n<p><strong>Formal charge = [Valence electrons] &#8211; [Lone electrons + \u00bd Bonding electrons]<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Nitrogen<\/strong>:<br>5 \u2013 (2 lone + 2 from single bond) = <strong>5 \u2013 4 = +1<\/strong><br>(BUT if it has 2 lone pairs: 5 \u2013 (4 + 2) = <strong>-1<\/strong>) \u2190 This is true in <strong>N\u207b\u2013C\u2261O\u207a<\/strong><\/li>\n\n\n\n<li><strong>Carbon<\/strong>:<br>4 \u2013 (0 lone + 4 bonding) = <strong>0<\/strong><\/li>\n\n\n\n<li><strong>Oxygen<\/strong> (triple bonded, 2 lone pairs):<br>6 \u2013 (4 + 3\u00d72 = 6) = <strong>6 \u2013 7 = -1<\/strong> \u2192 too negative. But in this case:<br>Oxygen has <strong>4 non-bonding electrons (2 pairs)<\/strong>, and 3 bonds = 6 electrons<br>6 \u2013 (4 + 3) = <strong>-1<\/strong> But we made a mistake! Let\u2019s double-check for best structure.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Best Lewis Structure<\/strong>:<\/h3>\n\n\n\n<p><strong>Structure: N=C=O\u207b<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>N double bonded to C, which is double bonded to O<\/li>\n\n\n\n<li>One lone pair on N, two on C, three on O<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Formal Charges:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Nitrogen<\/strong>: 5 \u2013 (2 lone + 2 bonds) = 5 \u2013 4 = <strong>+1<\/strong><\/li>\n\n\n\n<li><strong>Carbon<\/strong>: 4 \u2013 4 = <strong>0<\/strong><\/li>\n\n\n\n<li><strong>Oxygen<\/strong>: 6 \u2013 (6 lone + 2 bonding) = 6 \u2013 7 = <strong>-1<\/strong><\/li>\n<\/ul>\n\n\n\n<p>This makes <strong>formal charges<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>N: <strong>+1<\/strong><\/li>\n\n\n\n<li>C: <strong>0<\/strong><\/li>\n\n\n\n<li>O: <strong>\u20131<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Net charge: +1 + 0 \u2013 1 = <strong>0<\/strong> \u2192 not consistent with NCO\u207b<\/p>\n\n\n\n<p>So try <strong>structure N\u2013C\u2261O\u207b<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>N has one lone pair, single bonded to C<\/li>\n\n\n\n<li>C triple bonded to O<\/li>\n<\/ul>\n\n\n\n<p>Formal charges:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>N: 5 \u2013 (2 + 2) = <strong>+1<\/strong><\/li>\n\n\n\n<li>C: 4 \u2013 4 = <strong>0<\/strong><\/li>\n\n\n\n<li>O: 6 \u2013 (4 + 3) = <strong>\u20131<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Now total: +1 + 0 \u20131 = <strong>0<\/strong><\/p>\n\n\n\n<p>Still no. The most accurate best Lewis structure that <strong>adds to \u20131<\/strong> is:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>:N\u2261C\u2013O:\u207b<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>N triple bonded to C, single bonded to O\u207b<\/li>\n<\/ul>\n\n\n\n<p>Formal charges:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>N<\/strong>: 5 \u2013 (2 + 3) = 0<\/li>\n\n\n\n<li><strong>C<\/strong>: 4 \u2013 (4) = 0<\/li>\n\n\n\n<li><strong>O<\/strong>: 6 \u2013 (6 + 1) = <strong>\u20131<\/strong><\/li>\n<\/ul>\n\n\n\n<p>This is the <strong>best Lewis structure<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Correct Answer: <strong>D. In the best Lewis structure the formal charge of the nitrogen is -1<\/strong><\/h3>\n\n\n\n<p>However, based on above corrected formal charge:<\/p>\n\n\n\n<p>Actually <strong>this is incorrect<\/strong>, because in the best structure, nitrogen has <strong>0<\/strong> formal charge.<\/p>\n\n\n\n<p>Let\u2019s re-evaluate options:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Final Lewis structure<\/strong>: <code>:N\u2261C\u2013O:\u207b<\/code><\/li>\n\n\n\n<li>Formal charges: N = 0, C = 0, O = \u20131<\/li>\n<\/ul>\n\n\n\n<p>So, the correct statement is:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>B. In the best Lewis structure the formal charge of the oxygen is \u20131<\/strong><\/h3>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Final Answer: <strong>B<\/strong><\/h3>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Correct Statement: <em>In the best Lewis structure, the formal charge of the oxygen is \u20131.<\/em><\/h3>\n\n\n\n<p>This matches the total \u20131 charge of the ion, and places the negative charge on the most electronegative atom, <strong>oxygen<\/strong>, which makes the structure most stable.<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Draw the Lewis sructure for NCo, the oyanate anion, and calcle charges. Which statement is true: A. In the best Lewis structure the formal charge of the onygrn isB. In the best Lewis structure the formal charge of the osy gen isC. In the best Lewis structure the formal charge of the carbon isD. In [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-214800","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/214800","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=214800"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/214800\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=214800"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=214800"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=214800"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}