{"id":21538,"date":"2025-06-15T12:58:30","date_gmt":"2025-06-15T12:58:30","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=21538"},"modified":"2025-06-15T12:58:32","modified_gmt":"2025-06-15T12:58:32","slug":"steric-number-of-bh3-alh3-h2se","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/steric-number-of-bh3-alh3-h2se\/","title":{"rendered":"steric number of BH3, AlH3, H2Se"},"content":{"rendered":"\n<p>steric number of BH3, AlH3, H2Se?<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\"><strong>The correct answer and explanation is:<\/strong><\/mark><\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Correct Answers:<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>BH\u2083 (Borane):<\/strong> Steric number = <strong>3<\/strong><\/li>\n\n\n\n<li><strong>AlH\u2083 (Aluminum hydride):<\/strong> Steric number = <strong>3<\/strong><\/li>\n\n\n\n<li><strong>H\u2082Se (Hydrogen selenide):<\/strong> Steric number = <strong>4<\/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>Explanation (300 Words):<\/strong><\/h3>\n\n\n\n<p>The <strong>steric number<\/strong> is a concept used in molecular geometry to predict the shape of molecules. It is calculated using the formula:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p><strong>Steric number = Number of bonded atoms + Number of lone electron pairs on the central atom<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p>Let\u2019s analyze each compound:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>1. BH\u2083 (Borane):<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Central atom:<\/strong> Boron (B)<\/li>\n\n\n\n<li><strong>Bonded atoms:<\/strong> 3 hydrogen atoms<\/li>\n\n\n\n<li><strong>Lone pairs on B:<\/strong> 0 (boron only has 3 valence electrons and forms 3 bonds; it does not complete an octet)<\/li>\n\n\n\n<li><strong>Steric number = 3 + 0 = 3<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>Geometry:<\/strong> Trigonal planar<br><strong>Bond angle:<\/strong> Approximately 120\u00b0<br><strong>Note:<\/strong> BH\u2083 is electron-deficient and can act as a Lewis acid.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>2. AlH\u2083 (Aluminum hydride):<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Central atom:<\/strong> Aluminum (Al)<\/li>\n\n\n\n<li><strong>Bonded atoms:<\/strong> 3 hydrogen atoms<\/li>\n\n\n\n<li><strong>Lone pairs on Al:<\/strong> 0 (similar to boron, aluminum is in group 13 and forms 3 bonds without lone pairs)<\/li>\n\n\n\n<li><strong>Steric number = 3 + 0 = 3<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>Geometry:<\/strong> Trigonal planar<br><strong>Note:<\/strong> AlH\u2083 also does not satisfy the octet rule fully, and it is unstable as a monomer. It often exists as a polymer in solid state.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>3. H\u2082Se (Hydrogen selenide):<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Central atom:<\/strong> Selenium (Se)<\/li>\n\n\n\n<li><strong>Bonded atoms:<\/strong> 2 hydrogen atoms<\/li>\n\n\n\n<li><strong>Lone pairs on Se:<\/strong> 2 (Se is in group 16, has 6 valence electrons, uses 2 for bonding, leaving 4 electrons or 2 lone pairs)<\/li>\n\n\n\n<li><strong>Steric number = 2 + 2 = 4<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>Geometry:<\/strong> Bent (angular)<br><strong>Bond angle:<\/strong> Slightly less than 109.5\u00b0 due to lone pair repulsion<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>In summary, the steric number provides insight into a molecule&#8217;s 3D shape by counting bonded atoms and lone pairs. It plays a crucial role in predicting molecular geometry using VSEPR theory.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>steric number of BH3, AlH3, H2Se? The correct answer and explanation is: Correct Answers: Explanation (300 Words): The steric number is a concept used in molecular geometry to predict the shape of molecules. It is calculated using the formula: Steric number = Number of bonded atoms + Number of lone electron pairs on the central [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-21538","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/21538","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=21538"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/21538\/revisions"}],"predecessor-version":[{"id":21539,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/21538\/revisions\/21539"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=21538"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=21538"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=21538"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}