{"id":13246,"date":"2014-02-07T19:53:41","date_gmt":"2014-02-07T19:53:41","guid":{"rendered":"http:\/\/www.mometrix.com\/academy\/?page_id=13246"},"modified":"2026-04-28T11:17:57","modified_gmt":"2026-04-28T16:17:57","slug":"properties-of-alkanes","status":"publish","type":"page","link":"https:\/\/www.mometrix.com\/academy\/properties-of-alkanes\/","title":{"rendered":"Properties of Alkanes"},"content":{"rendered":"\n\t\t\t<div id=\"mmDeferVideoEncompass_HYpXOST9YZE\" style=\"position: relative;\">\n\t\t\t<picture>\n\t\t\t\t<source srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/01\/circle-play-duotone.webp\" type=\"image\/webp\">\n\t\t\t\t<source srcset=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/01\/circle-play-duotone.png\" type=\"image\/jpeg\"> \n\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" loading=\"eager\" id=\"videoThumbnailImage_HYpXOST9YZE\" data-source-videoID=\"HYpXOST9YZE\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/01\/circle-play-duotone.png\" alt=\"Properties of Alkanes Video\" height=\"464\" width=\"825\" class=\"size-full\" data-matomo-title = \"Properties of Alkanes\">\n\t\t\t<\/picture>\n\t\t\t<\/div>\n\t\t\t<style>img#videoThumbnailImage_HYpXOST9YZE:hover {cursor:pointer;} img#videoThumbnailImage_HYpXOST9YZE {background-size:contain;background-image:url(\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2023\/02\/656-properties-of-alkanes-2.webp\");}<\/style>\n\t\t\t<script defer>\n\t\t\t  jQuery(\"img#videoThumbnailImage_HYpXOST9YZE\").click(function() {\n\t\t\t\tlet videoId = jQuery(this).attr(\"data-source-videoID\");\n\t\t\t\tlet helpTag = '<div id=\"mmDeferVideoYTMessage_HYpXOST9YZE\" style=\"display: none;position: absolute;top: -24px;width: 100%;text-align: center;\"><span style=\"font-style: italic;font-size: small;border-top: 1px solid #fc0;\">Having trouble? <a href=\"https:\/\/www.youtube.com\/watch?v='+videoId+'\" target=\"_blank\">Click here to watch on YouTube.<\/a><\/span><\/div>';\n\t\t\t\tlet tag = document.createElement(\"iframe\");\n\t\t\t\ttag.id = \"yt\" + videoId;\n\t\t\t\ttag.src = \"https:\/\/www.youtube-nocookie.com\/embed\/\" + videoId + \"?autoplay=1&controls=1&wmode=opaque&rel=0&egm=0&iv_load_policy=3&hd=0&enablejsapi=1\";\n\t\t\t\ttag.frameborder = 0;\n\t\t\t\ttag.allow = \"autoplay; fullscreen\";\n\t\t\t\ttag.width = this.width;\n\t\t\t\ttag.height = this.height;\n\t\t\t\ttag.setAttribute(\"data-matomo-title\",\"Properties of Alkanes\");\n\t\t\t\tjQuery(\"div#mmDeferVideoEncompass_HYpXOST9YZE\").html(tag);\n\t\t\t\tjQuery(\"div#mmDeferVideoEncompass_HYpXOST9YZE\").prepend(helpTag);\n\t\t\t\tsetTimeout(function(){jQuery(\"div#mmDeferVideoYTMessage_HYpXOST9YZE\").css(\"display\", \"block\");}, 2000);\n\t\t\t  });\n\t\t\t  \n\t\t\t<\/script>\n\t\t\n<p><script>\nfunction Wc0_Function() {\n  var x = document.getElementById(\"Wc0\");\n  if (x.style.display === \"none\") {\n    x.style.display = \"block\";\n  } else {\n    x.style.display = \"none\";\n  }\n}\n<\/script><\/p>\n<div class=\"moc-toc hide-on-desktop hide-on-tablet\">\n<div><button onclick=\"Wc0_Function()\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/www.mometrix.com\/academy\/wp-content\/uploads\/2024\/12\/toc2.svg\" width=\"16\" height=\"16\" alt=\"show or hide table of contents\"><\/button><\/p>\n<p>On this page<\/p>\n<\/div>\n<nav id=\"Wc0\" style=\"display:none;\">\n<ul>\n<li class=\"toc-h2\"><a href=\"#Alkane_Structure\" class=\"smooth-scroll\">Alkane Structure<\/a><\/li>\n<li class=\"toc-h2\"><a href=\"#Properties_of_Alkanes\" class=\"smooth-scroll\">Properties of Alkanes<\/a><\/li>\n<li class=\"toc-h2\"><a href=\"#Review\" class=\"smooth-scroll\">Review<\/a><\/li>\n<\/ul>\n<\/nav>\n<\/div>\n<div class=\"accordion\"><input id=\"transcript\" type=\"checkbox\" class=\"spoiler_button\" \/><label for=\"transcript\">Transcript<\/label>\n<div class=\"spoiler\" id=\"transcript-spoiler\">\n<p>Hi, and welcome to this video on alkanes!<\/p>\n<h2><span id=\"Alkane_Structure\" class=\"m-toc-anchor\"><\/span>Alkane Structure<\/h2>\n<p>\nAlkanes are saturated hydrocarbons. This means they are made of just carbon and hydrogen and that there are no double or triple carbon-carbon bonds.  <\/p>\n<h3><span id=\"Building_Butane\" class=\"m-toc-anchor\"><\/span>Building Butane<\/h3>\n<p>\nTo better understand this, let\u2019s build \\(n\\)-Butane, a four-carbon straight-chain alkane.<\/p>\n<p>First, we put our carbons in a row and connect them with a single bond. This is our <strong>carbon backbone<\/strong>.  <\/p>\n<p>Carbon atoms have four electrons in the valence shell and, as such, make four bonds to satisfy the octet rule. In alkanes, any non-carbon bond will be to a hydrogen, which is referred to as saturating a carbon with hydrogen. <\/p>\n<p>For our example of <strong>butane<\/strong>, the two terminal carbons will be bonded to three hydrogens and the two interior carbons will be bonded to two hydrogens. <\/p>\n<p>This gives us the final structure and the chemical formula C<sub>4<\/sub>H<sub>10<\/sub>.<\/p>\n<h3><span id=\"General_Alkane_Formula\" class=\"m-toc-anchor\"><\/span>General Alkane Formula<\/h3>\n<p>\nAll straight-chain and branched alkanes have the general chemical formula C<sub>n<\/sub>H<sub>2n+2<\/sub>. In the case of butane, \\(n=4\\), so there are four carbons and \\(2(4)+2 = 10\\) hydrogens. <\/p>\n<h3><span id=\"LineAngle_Structures\" class=\"m-toc-anchor\"><\/span>Line-Angle Structures<\/h3>\n<p>\nWhile this depiction of butane is chemically informative, it\u2019s pretty cumbersome to write out every time, so chemists use a shorthand form that just shows the carbon backbone.<\/p>\n<p>This zig-zag represents butane. Carbon atoms are at each point and each line represents a carbon-carbon single bond. The hydrogens have been removed and we simply assume their presence. These simplified drawings are highly preferred in organic chemistry, so it\u2019s helpful to get comfortable with them early.<\/p>\n<h3><span id=\"Hybridization_and_Geometry\" class=\"m-toc-anchor\"><\/span>Hybridization and Geometry<\/h3>\n<p>\nThe carbons in alkanes are bonded to four constituents, which means they are sp<sup>3<\/sup>-hybridized. This means that the 2s orbitals and the three 2p orbitals of the carbon atom have combined to make four equal sp<sup>3<\/sup> orbitals. <\/p>\n<p>These orbitals overlap with the sp<sup>3<\/sup> orbitals of other carbons or the 1s orbitals of the hydrogen to make sigma bonds, which are the strongest covalent bonds. <\/p>\n<p>The four bonds are spaced equally around the carbon, which yields a tetrahedral geometry. This means that the carbon backbone zig-zags, just as the line drawing represented.<\/p>\n<p>The main takeaway from all this is that in alkanes, every carbon has four strong sigma bonds. This will be important later when we talk about the properties of alkanes. <\/p>\n<h3><span id=\"StraightChain,_Branched,_and_Cyclic_Hydrocarbons\" class=\"m-toc-anchor\"><\/span>Straight-Chain, Branched, and Cyclic Hydrocarbons<\/h3>\n<p>\nAlong with simple straight-chain alkanes like butane, alkanes can also be branched. For example, <strong>isobutane<\/strong>, an isomer of butane, is also an alkane as it follows the C<sub>n<\/sub>H<sub>2n+2<\/sub> formula. <\/p>\n<p>Strictly speaking, <strong>cyclic carbon frames<\/strong> saturated with hydrogen (for example, cyclohexane) are not considered alkanes because they do not follow the chemical formula C<sub>n<\/sub>H<sub>2n+2<\/sub> (two of the hydrogens have been replaced by the carbon-carbon bond that closes the ring). However, it\u2019s not uncommon to see cyclical compounds referred to as alkanes in less formal settings.  <\/p>\n<p>Now that we\u2019re familiar with the structure of alkanes, let\u2019s look at their properties. <\/p>\n<h2><span id=\"Properties_of_Alkanes\" class=\"m-toc-anchor\"><\/span>Properties of Alkanes<\/h2>\n<h3><span id=\"Nonpolarity_and_Low_Reactivity\" class=\"m-toc-anchor\"><\/span>Nonpolarity and Low Reactivity<\/h3>\n<p>\nAlkanes are <strong>nonpolar<\/strong> and thus insoluble in <a class=\"ylist\" href=\"https:\/\/www.mometrix.com\/academy\/properties-of-water\/\">water<\/a>.<\/p>\n<p>They are also fairly unreactive. This is for a few reasons. First, because alkanes are nonpolar, there are no areas of partial charge. This means that they do not strongly attract other molecules with partial charge, which is often how reactions start. Second, to form new bonds, the strong sigma bonds we described earlier, would have to be broken. While this isn\u2019t impossible, it\u2019s not the easiest chemistry and it\u2019s usually hard to control.<\/p>\n<h3><span id=\"Combustion_and_Oxidation\" class=\"m-toc-anchor\"><\/span>Combustion and Oxidation<\/h3>\n<p>\nThat being said, as carbons are highly <strong>unoxidized<\/strong>, they are perfect for oxidation-reduction reactions and are commonly used as combustion fuels (think of propane\u2013a three-carbon straight-chain alkane\u2013in your gas grill). <\/p>\n<p>Even though most alkanes are relatively uncommon in nature, it is helpful for chemists and biologists to study their structures and properties. Take for example <strong>butanoic acid<\/strong>, a compound found in animal fat, plant oils, cow\u2019s milk, and breast milk. While it isn\u2019t an alkane, you can easily see the underlying 4-carbon alkane within it. In fact, you\u2019ll notice that the name of the alkane\u2014butane\u2014is the root word for butanoic acid.  <\/p>\n<p>Vitamin E and open-chain glucose are more complex molecules, but you can still see the underlying carbon frames in both. <\/p>\n<p>A useful analogy is to think of the carbon frame as the trunk and branches of the tree and the functional groups as the leaves and fruits hanging from the tree. <\/p>\n<hr>\n<h2><span id=\"Review\" class=\"m-toc-anchor\"><\/span>Review<\/h2>\n<p>\nLet\u2019s finish with a review.<\/p>\n<p>We first defined alkanes as a <strong>saturated hydrocarbon<\/strong> with the general chemical formula of C<sub>n<\/sub>H<sub>2n+2<\/sub>. We built n-butane, a simple 4-carbon alkane, and learned the shorthand method for drawing alkanes.<\/p>\n<p>We then considered the sp<sup>3<\/sup>-hybridization of the carbon atoms, connecting this both to the structure and inertness of alkanes. Finally, we looked at a few examples to demonstrate how alkanes provide the carbon framework for many <a class=\"ylist\" href=\"https:\/\/www.mometrix.com\/academy\/organic-compounds\/\">organic compounds<\/a>.   <\/p>\n<p>Thanks for watching, and happy studying!<\/p>\n<\/div>\n<\/div>\n\n<div class=\"home-buttons\">\n<p><a href=\"https:\/\/www.mometrix.com\/academy\/chemistry\/\">Return to Chemistry Videos<\/a><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Return to Chemistry Videos<\/p>\n","protected":false},"author":1,"featured_media":95593,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":{"0":"post-13246","1":"page","2":"type-page","3":"status-publish","4":"has-post-thumbnail","6":"page_category-organic-chemistry-videos","7":"page_type-video","8":"subject_matter-science"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages\/13246","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/comments?post=13246"}],"version-history":[{"count":5,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages\/13246\/revisions"}],"predecessor-version":[{"id":292583,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/pages\/13246\/revisions\/292583"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/media\/95593"}],"wp:attachment":[{"href":"https:\/\/www.mometrix.com\/academy\/wp-json\/wp\/v2\/media?parent=13246"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}