{"id":247168,"date":"2025-07-07T15:10:17","date_gmt":"2025-07-07T15:10:17","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=247168"},"modified":"2025-07-07T15:10:19","modified_gmt":"2025-07-07T15:10:19","slug":"determine-the-oxidation-number","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/07\/determine-the-oxidation-number\/","title":{"rendered":"Determine the oxidation number"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

Here are the correct oxidation numbers for the underlined elements, followed by a detailed explanation.<\/p>\n\n\n\n

Answers:<\/strong><\/p>\n\n\n\n

    \n
  1. S in H\u2082SO\u2084:\u00a0+6<\/strong><\/li>\n\n\n\n
  2. S in HSO\u2084\u207b:\u00a0+6<\/strong><\/li>\n\n\n\n
  3. P in P\u2084:\u00a00<\/strong><\/li>\n\n\n\n
  4. H in NaH:\u00a0-1<\/strong><\/li>\n\n\n\n
  5. U in UO\u2083:\u00a0+6<\/strong><\/li>\n\n\n\n
  6. O in Na\u2082O\u2082:\u00a0-1<\/strong><\/li>\n\n\n\n
  7. U in U\u2082O\u2085:\u00a0+5<\/strong><\/li>\n\n\n\n
  8. Pb in PbSO\u2084:\u00a0+2<\/strong><\/li>\n<\/ol>\n\n\n\n

    Explanation:<\/strong><\/p>\n\n\n\n

    Oxidation numbers are assigned to atoms in a molecule or ion based on a set of rules that help track electron distribution. The fundamental principle is that the sum of the oxidation numbers of all atoms in a species must equal its overall charge. For a neutral compound, this sum is zero, while for an ion, it equals the ion’s charge.<\/p>\n\n\n\n

    We start by assigning known oxidation numbers to certain elements. Oxygen is almost always -2, and hydrogen is +1 when bonded to nonmetals. In sulfuric acid (H\u2082SO\u2084), we have two hydrogens (2 x +1 = +2) and four oxygens (4 x -2 = -8). For the compound to be neutral, the sulfur (S) must have an oxidation number of +6 to balance the charges. The calculation is similar for the hydrogen sulfate ion (HSO\u2084\u207b). With one hydrogen (+1) and four oxygens (-8), the sum is -7. For the ion to have its -1 charge, sulfur must again be +6.<\/p>\n\n\n\n

    There are important exceptions to these general rules. Any element in its pure, elemental form has an oxidation number of 0, which is why phosphorus in P\u2084 is 0. In metal hydrides like sodium hydride (NaH), hydrogen is bonded to a less electronegative metal. Sodium (Na), a group 1 metal, is always +1, so hydrogen must be -1 to balance the compound. In peroxides like sodium peroxide (Na\u2082O\u2082), oxygen has an oxidation number of -1. Here, the two sodium atoms contribute a total of +2, so the two oxygen atoms must total -2, making each one -1.<\/p>\n\n\n\n

    For the uranium oxides, we use the standard -2 for oxygen. In UO\u2083, three oxygens create a total charge of -6, so the single uranium (U) atom must be +6. In U\u2082O\u2085, five oxygens total -10. This charge must be balanced by two uranium atoms, meaning each uranium has an oxidation number of +5. Finally, in lead(II) sulfate (PbSO\u2084), we can recognize the sulfate polyatomic ion (SO\u2084\u00b2\u207b), which has a -2 charge. To make the compound neutral, the lead (Pb) atom must have an oxidation number of +2.<\/p>\n\n\n\n

    \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

    The Correct Answer and Explanation is: Here are the correct oxidation numbers for the underlined elements, followed by a detailed explanation. Answers: Explanation: Oxidation numbers are assigned to atoms in a molecule or ion based on a set of rules that help track electron distribution. The fundamental principle is that the sum of the oxidation […]<\/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-247168","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/247168","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=247168"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/247168\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=247168"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=247168"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=247168"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}