{"id":12537,"date":"2026-05-12T13:24:45","date_gmt":"2026-05-12T13:24:45","guid":{"rendered":"https:\/\/www.vedprep.com\/exams\/?p=12537"},"modified":"2026-05-12T14:15:32","modified_gmt":"2026-05-12T14:15:32","slug":"langmuir-adsorption-isotherm-2","status":"publish","type":"post","link":"https:\/\/www.vedprep.com\/exams\/iit-jam\/langmuir-adsorption-isotherm-2\/","title":{"rendered":"Langmuir adsorption isotherm For IIT JAM 2027"},"content":{"rendered":"<p>The <strong>Langmuir adsorption isotherm<\/strong> is a mathematical model used to describe the adsorption of molecules onto a surface. It is a fundamental concept in physical chemistry and is often tested in IIT JAM and CSIR NET exams.<\/p>\n<h2 data-path-to-node=\"0\"><strong>Understanding Langmuir Adsorption Isotherm: Syllabus and Key Textbooks<\/strong><\/h2>\n<p data-path-to-node=\"1\">If you\u2019re gearing up for the <a href=\"https:\/\/jam2026.iitb.ac.in\/files\/syllabus_CY.pdf\" rel=\"nofollow noopener\" target=\"_blank\"><strong>IIT JAM<\/strong><\/a>, you\u2019ve probably realized that <b data-path-to-node=\"1\" data-index-in-node=\"68\">Surface Chemistry<\/b> is one of those units where you can really score well if you get the basics right. The <b data-path-to-node=\"1\" data-index-in-node=\"173\">Langmuir adsorption isotherm<\/b> is a superstar in this section. It\u2019s not just a fancy equation; it\u2019s a fundamental way to describe how gas molecules &#8220;stick&#8221; to a solid surface.<\/p>\n<p data-path-to-node=\"2\">At <a href=\"https:\/\/www.vedprep.com\/online-courses\"><strong>VedPrep<\/strong><\/a>, we\u2019ve noticed that students often get overwhelmed by the math, but it\u2019s actually pretty straightforward once you see the logic behind it while covering areas such as <strong>Langmuir adsorption isotherm<\/strong>. You\u2019ll find this topic under Physical Chemistry in the official syllabus. If you want to dive deeper, Atkins&#8217; Physical Chemistry is the classic go-to. For those who want to get their hands dirty with practice problems, Irodov\u2019s General Physics has some great challenges, though it can be a bit intense.<\/p>\n<h2 data-path-to-node=\"4\"><strong>Langmuir Adsorption Isotherm For IIT JAM: Main Concept Explanation<\/strong><\/h2>\n<p data-path-to-node=\"5\">Imagine you\u2019re at a busy coffee shop (like the one we\u2019re virtually sitting in) and there are only ten bar stools. Once someone sits on a stool, that spot is taken. No one can sit on top of them, and nobody is fighting over the same seat. This is basically what the <b data-path-to-node=\"5\" data-index-in-node=\"265\">Langmuir adsorption isotherm<\/b> describes\u2014but with molecules and surfaces.<\/p>\n<p data-path-to-node=\"5\">The equation looks like this:<\/p>\n<p data-path-to-node=\"5\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-15898 aligncenter\" src=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Langmuir-Adsorption-Isotherm.png\" alt=\"Langmuir Adsorption Isotherm\" width=\"172\" height=\"87\" \/><\/p>\n<p data-path-to-node=\"8\">Here, <span class=\"math-inline\" data-math=\"\\theta\" data-index-in-node=\"6\">\u03b8<\/span> is the &#8220;surface coverage&#8221; (think of it as the percentage of bar stools occupied), <span class=\"math-inline\" data-math=\"P\" data-index-in-node=\"95\">P<\/span> is the pressure of the gas, and <span class=\"math-inline\" data-math=\"b\" data-index-in-node=\"129\">b<\/span>\u00a0is a constant that tells us how strongly the gas wants to stick to the surface.<\/p>\n<p data-path-to-node=\"9\">This model relies on a few big &#8220;what ifs&#8221; (assumptions):<\/p>\n<ul data-path-to-node=\"10\">\n<li>\n<p data-path-to-node=\"10,0,0\"><b data-path-to-node=\"10,0,0\" data-index-in-node=\"0\">A Flat Playground:<\/b> The surface is perfectly smooth and uniform (homogeneous). Every &#8220;seat&#8221; is identical.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"10,1,0\"><b data-path-to-node=\"10,1,0\" data-index-in-node=\"0\">One Layer Only:<\/b> Once a molecule grabs a spot, no other molecule can pile on top of it. It\u2019s a monolayer.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"10,2,0\"><b data-path-to-node=\"10,2,0\" data-index-in-node=\"0\">Mind Your Own Business:<\/b> The molecules don\u2019t interact with their neighbors. They just sit there and mind their own business.<\/p>\n<\/li>\n<\/ul>\n<p data-path-to-node=\"11\">Of course, real life is messier. Real surfaces have &#8220;potholes&#8221; (defects), and sometimes molecules like to pile up in layers. That\u2019s where this model falls a bit short, but for the JAM, mastering these basics is your first step to success.<\/p>\n<h2 data-path-to-node=\"13\"><strong>Worked Example<\/strong><\/h2>\n<p data-path-to-node=\"14\">Let&#8217;s look at a quick calculation. Suppose a gas is hitting a surface at 1 atm pressure. If our constant <span class=\"math-inline\" data-math=\"b\" data-index-in-node=\"105\">b<\/span>\u00a0is 0.1, what&#8217;s the coverage?<\/p>\n<p data-path-to-node=\"15\">Using the formula:<\/p>\n<p data-path-to-node=\"15\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-15899 aligncenter\" src=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Langmuir-Adsorption-Isotherm-example-300x90.png\" alt=\"Langmuir Adsorption Isotherm example\" width=\"300\" height=\"90\" srcset=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Langmuir-Adsorption-Isotherm-example-300x90.png 300w, https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Langmuir-Adsorption-Isotherm-example.png 372w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>So, about 9.1% of our surface is covered. It&#8217;s like having a 100-seat lecture hall and only 9 students showing up\u2014plenty of room left! At (Company Name), we suggest playing around with these numbers to see how increasing the pressure <span class=\"math-inline\" data-math=\"P\" data-index-in-node=\"234\">P<\/span>\u00a0eventually fills up the surface.<\/p>\n<h2 data-path-to-node=\"19\"><strong>Common Misconceptions About Langmuir Adsorption Isotherm For IIT JAM<\/strong><\/h2>\n<p data-path-to-node=\"20\">A big trap students fall into is thinking the surface can be &#8220;bumpy&#8221; or varied (heterogeneous). In Langmuir\u2019s world, every single spot on that surface is exactly the same. If you start talking about different energy levels on the same surface, you\u2019ve moved out of Langmuir territory.<\/p>\n<p data-path-to-node=\"21\">Another common slip-up is forgetting that this is <b data-path-to-node=\"21\" data-index-in-node=\"50\">monolayer<\/b> only. If the question mentions molecules stacking like a skyscraper, Langmuir isn&#8217;t your guy. Remembering these small details can be the difference between a &#8220;plus mark&#8221; and a &#8220;minus mark&#8221; on your exam paper.<\/p>\n<h2 data-path-to-node=\"23\"><strong>Real-World Applications<\/strong><\/h2>\n<p data-path-to-node=\"24\">This isn&#8217;t just for passing exams; this stuff is everywhere.<\/p>\n<ul data-path-to-node=\"25\">\n<li>\n<p data-path-to-node=\"25,0,0\"><b data-path-to-node=\"25,0,0\" data-index-in-node=\"0\">Cleaning Water:<\/b> Think of activated carbon in a water filter. It\u2019s like a giant sponge for pollutants. The dye molecules stick to the carbon surface just like the gas molecules in our model.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"25,1,0\"><b data-path-to-node=\"25,1,0\" data-index-in-node=\"0\">Gas Separation:<\/b> Zeolites act like high-tech filters that grab specific gases while letting others pass by.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"25,2,0\"><b data-path-to-node=\"25,2,0\" data-index-in-node=\"0\">Health Tech:<\/b> Many biosensors work by having specific proteins stick to a surface to trigger a reading.<\/p>\n<\/li>\n<\/ul>\n<p data-path-to-node=\"26\">At <a href=\"https:\/\/www.vedprep.com\/online-courses\/iit-jam\"><strong>VedPrep<\/strong><\/a>, we find that thinking about these real-world uses makes the &#8220;dry&#8221; equations a lot more interesting to study.<\/p>\n<h2 data-path-to-node=\"28\"><strong>Exam Strategy for Langmuir Adsorption Isotherm For IIT JAM<\/strong><\/h2>\n<p data-path-to-node=\"29\">When you\u2019re sitting in that exam hall, don&#8217;t just jump into the math. Read the question carefully to see if the assumptions hold up. If the problem mentions &#8220;low pressure,&#8221; remember that the equation simplifies to \u03b8<span class=\"math-inline\" data-math=\"\\theta \\approx bP\" data-index-in-node=\"214\"> \u2248 bP<\/span>. If it\u2019s &#8220;high pressure,&#8221; the surface is saturated, and \u03b8 stays close to 1.<\/p>\n<p data-path-to-node=\"30\">Practice is everything. Try to solve for <span class=\"math-inline\" data-math=\"b\" data-index-in-node=\"41\">b<\/span> or <span class=\"math-inline\" data-math=\"P\" data-index-in-node=\"46\">P<\/span>\u00a0by rearranging the formula. We recommend looking at previous years&#8217; papers to see how they twist these questions. It\u2019s usually about finding one missing variable while keeping the assumptions in mind.<\/p>\n<h2><strong>Comparison of Langmuir Adsorption Isotherm with Other Adsorption Isotherms<\/strong><\/h2>\n<p>Not all isotherms are created equal. Here\u2019s a quick breakdown:<\/p>\n<table data-path-to-node=\"34\">\n<thead>\n<tr>\n<td><strong>Isotherm<\/strong><\/td>\n<td><strong>Surface Type<\/strong><\/td>\n<td><strong>Layers<\/strong><\/td>\n<td><strong>Best Used For<\/strong><\/td>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><span data-path-to-node=\"34,1,0,0\"><b data-path-to-node=\"34,1,0,0\" data-index-in-node=\"0\">Langmuir<\/b><\/span><\/td>\n<td><span data-path-to-node=\"34,1,1,0\">Homogeneous<\/span><\/td>\n<td><span data-path-to-node=\"34,1,2,0\">Monolayer<\/span><\/td>\n<td><span data-path-to-node=\"34,1,3,0\">Basic gas-solid adsorption<\/span><\/td>\n<\/tr>\n<tr>\n<td><span data-path-to-node=\"34,2,0,0\"><b data-path-to-node=\"34,2,0,0\" data-index-in-node=\"0\">Freundlich<\/b><\/span><\/td>\n<td><span data-path-to-node=\"34,2,1,0\">Heterogeneous<\/span><\/td>\n<td><span data-path-to-node=\"34,2,2,0\">Multilayer (can be)<\/span><\/td>\n<td><span data-path-to-node=\"34,2,3,0\">Complex, &#8220;rough&#8221; surfaces<\/span><\/td>\n<\/tr>\n<tr>\n<td><span data-path-to-node=\"34,3,0,0\"><b data-path-to-node=\"34,3,0,0\" data-index-in-node=\"0\">BET<\/b><\/span><\/td>\n<td><span data-path-to-node=\"34,3,1,0\">Homogeneous<\/span><\/td>\n<td><span data-path-to-node=\"34,3,2,0\">Multilayer<\/span><\/td>\n<td><span data-path-to-node=\"34,3,3,0\">Finding the total surface area<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><strong>Practice Problems &#8211; Langmuir Adsorption Isotherm For IIT JAM<\/strong><\/h2>\n<p data-path-to-node=\"38\">Let&#8217;s try one more to keep your brain sharp.<\/p>\n<p data-path-to-node=\"39\">Suppose you have a gas where <span class=\"math-inline\" data-math=\"b = 0.5\" data-index-in-node=\"29\">b = 0.5<\/span>\u00a0and the pressure is 2 atm.<\/p>\n<p data-path-to-node=\"39\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-15902 aligncenter\" src=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Practice-Problems-Langmuir-Adsorption-Isotherm-For-IIT-JAM-300x79.png\" alt=\"Practice Problems - Langmuir Adsorption Isotherm For IIT JAM\" width=\"300\" height=\"79\" srcset=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Practice-Problems-Langmuir-Adsorption-Isotherm-For-IIT-JAM-300x79.png 300w, https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Practice-Problems-Langmuir-Adsorption-Isotherm-For-IIT-JAM.png 382w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p data-path-to-node=\"39\">In this case, the surface is exactly half-full. If you can do that, you&#8217;re already on the right track! Keeping things simple and focusing on the core logic is how we at (Company Name) like to approach these topics. Good luck with your prep\u2014you\u2019ve got this!<\/p>\n<h2 data-path-to-node=\"39\"><strong>Final Thoughts\u00a0<\/strong><\/h2>\n<p data-path-to-node=\"39\">The <b data-path-to-node=\"1\" data-index-in-node=\"27\">Langmuir adsorption isotherm<\/b> isn&#8217;t just a scary-looking equation to memorize for the IIT JAM; it\u2019s a logical way to look at how molecules find a home on a surface. Whether you&#8217;re thinking about how a water filter cleans your drink or how a biosensor detects a virus, the core idea is the same: once a spot is taken, it&#8217;s taken. At <strong>VedPrep<\/strong>, we know that exam prep can feel like a marathon, but breaking down these physical chemistry concepts into relatable scenarios makes the finish line feel a lot closer. Keep practicing those numericals, stay clear on your assumptions, and you&#8217;ll be well on your way to acing the surface chemistry section.<\/p>\n<p data-path-to-node=\"39\">To know more in detail from our faculty, watch our YouTube video:<\/p>\n<p class=\"responsive-video-wrap clr\"><iframe title=\"Surface Chemistry | Physical Chemistry | Capsule Course |Part-2|IIT JAM|CSIR NET|GATE| Chem Academy\" width=\"1200\" height=\"675\" src=\"https:\/\/www.youtube.com\/embed\/VY_275NuRC4?list=PLdZcCa6mtW21nnnBxv13THPr99MxKMmrO\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<section>\n<h2><strong>Frequently Asked Questions<\/strong><\/h2>\n<\/section>\n<style>#sp-ea-15905 .spcollapsing { height: 0; overflow: hidden; transition-property: height;transition-duration: 300ms;}#sp-ea-15905.sp-easy-accordion>.sp-ea-single {margin-bottom: 10px; border: 1px solid #e2e2e2; }#sp-ea-15905.sp-easy-accordion>.sp-ea-single>.ea-header a {color: #444;}#sp-ea-15905.sp-easy-accordion>.sp-ea-single>.sp-collapse>.ea-body {background: #fff; color: #444;}#sp-ea-15905.sp-easy-accordion>.sp-ea-single {background: #eee;}#sp-ea-15905.sp-easy-accordion>.sp-ea-single>.ea-header a .ea-expand-icon { float: left; color: #444;font-size: 16px;}<\/style><div id=\"sp_easy_accordion-1778592535\">\n<div id=\"sp-ea-15905\" class=\"sp-ea-one sp-easy-accordion\" data-ea-active=\"ea-click\" data-ea-mode=\"vertical\" data-preloader=\"\" data-scroll-active-item=\"\" data-offset-to-scroll=\"0\">\n\n<!-- Start accordion card div. -->\n<div class=\"ea-card ea-expand sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159050\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159050\" aria-controls=\"collapse159050\" href=\"#\"  aria-expanded=\"true\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-minus\"><\/i> What exactly does the Langmuir adsorption isotherm tell us?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse collapsed show\" id=\"collapse159050\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159050\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>In plain English, it\u2019s a formula that predicts how much of a gas will stick to a solid surface at a specific pressure. It helps us figure out when a surface will become \"saturated\" or full.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159051\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159051\" aria-controls=\"collapse159051\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Why is it called an \"isotherm\"?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159051\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159051\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>\"Iso\" means same, and \"therm\" means temperature. We call it an isotherm because the whole process is studied while keeping the temperature constant. If you change the temperature, the equilibrium\u2014and the graph\u2014shifts.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159052\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159052\" aria-controls=\"collapse159052\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What are the three big assumptions I need to remember for IIT JAM?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159052\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159052\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Just remember: homogeneous surface (all spots are equal), monolayer (no stacking), and no lateral interactions (molecules don't talk to or push their neighbors).<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159053\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159053\" aria-controls=\"collapse159053\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What does the \"b\" in the equation represent?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159053\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159053\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>The constant <span class=\"math-inline\" data-math=\"b\" data-index-in-node=\"61\">b<\/span> is essentially the \"stickiness\" factor. It\u2019s the ratio of the rate of adsorption to the rate of desorption. A higher <span class=\"math-inline\" data-math=\"b\" data-index-in-node=\"180\">b<\/span>\u00a0value means the gas really likes staying on the surface.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159054\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159054\" aria-controls=\"collapse159054\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Does Langmuir account for \"physical\" or \"chemical\" adsorption?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159054\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159054\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>While it can be used for both, its assumption of a single monolayer makes it a much better fit for <b data-path-to-node=\"8\" data-index-in-node=\"165\">chemisorption<\/b>, where molecules form strong chemical bonds with the surface.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159055\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159055\" aria-controls=\"collapse159055\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Why doesn't Langmuir work at very high pressures in real life?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159055\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159055\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>In reality, once the first layer is full, gas molecules often start piling on top of each other. Langmuir\u2019s model says \"no stacking allowed,\" so it fails when multilayer adsorption starts happening.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159056\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159056\" aria-controls=\"collapse159056\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What happens to the equation at very low pressure?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159056\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159056\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>At low pressure, the <span class=\"math-inline\" data-math=\"bP\" data-index-in-node=\"75\">bP<\/span> in the denominator becomes tiny compared to 1. The equation simplifies to \u03b8<span class=\"math-inline\" data-math=\"\\theta = bP\" data-index-in-node=\"152\">= bP<\/span>. This means the coverage is directly proportional to the pressure.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159057\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159057\" aria-controls=\"collapse159057\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Can I use Langmuir for liquids?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159057\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159057\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Yes. You can adapt it for solutes in a solution. Instead of pressure (<span class=\"math-inline\" data-math=\"P\" data-index-in-node=\"106\">P<\/span>), you just use the concentration (<span class=\"math-inline\" data-math=\"C\" data-index-in-node=\"142\">C<\/span>) of the substance in the liquid.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159058\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159058\" aria-controls=\"collapse159058\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is \"surface coverage\" (\u03b8)?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159058\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159058\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>It\u2019s just a fraction. If <span class=\"math-inline\" data-math=\"\\theta\" data-index-in-node=\"66\">\u03b8<\/span>\u00a0is 0.7, it means 70% of the available spots on the adsorbent are occupied by gas molecules.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-159059\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159059\" aria-controls=\"collapse159059\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Does the Langmuir model consider the size of the molecules?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse159059\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-159059\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Not directly in the basic equation. It assumes each molecule takes up exactly one site, regardless of how big or small the molecule actually is.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-1590510\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1590510\" aria-controls=\"collapse1590510\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What's a real-life example of a \"homogeneous\" surface?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse1590510\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-1590510\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Perfectly smooth single crystals in a lab are close. However, most things we use at VedPrep, like charcoal or clay, are actually quite \"bumpy\" and heterogeneous.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-1590511\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1590511\" aria-controls=\"collapse1590511\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> Is adsorption exothermic or endothermic according to this model?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse1590511\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-1590511\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Adsorption is generally <b data-path-to-node=\"17\" data-index-in-node=\"93\">exothermic<\/b> (releases heat). According to Le Chatelier\u2019s principle, if you crank up the heat, the amount of gas adsorbed will actually go down.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-1590512\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1590512\" aria-controls=\"collapse1590512\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> What is the \"saturation\" point?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse1590512\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-1590512\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>That's the moment when every single available site on the surface is occupied. No matter how much more pressure you add, you can't stick any more molecules onto the surface.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-1590513\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1590513\" aria-controls=\"collapse1590513\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> How often does this show up in IIT JAM?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse1590513\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-1590513\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Almost every year! Whether it's a direct numerical or a conceptual question about the assumptions, it\u2019s a high-yield topic you shouldn't skip.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<!-- Start accordion card div. -->\n<div class=\"ea-card  sp-ea-single\">\n\t<!-- Start accordion header. -->\n\t<h3 class=\"ea-header\">\n\t\t<!-- Add anchor tag for header. -->\n\t\t<a class=\"collapsed\" id=\"ea-header-1590514\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1590514\" aria-controls=\"collapse1590514\" href=\"#\"  aria-expanded=\"false\" tabindex=\"0\">\n\t\t<i aria-hidden=\"true\" role=\"presentation\" class=\"ea-expand-icon eap-icon-ea-expand-plus\"><\/i> How do I calculate the volume of gas adsorbed at STP using Langmuir?\t\t<\/a> <!-- Close anchor tag for header. -->\n\t<\/h3>\t<!-- Close header tag. -->\n\t<!-- Start collapsible content div. -->\n\t<div class=\"sp-collapse spcollapse \" id=\"collapse1590514\" data-parent=\"#sp-ea-15905\" role=\"region\" aria-labelledby=\"ea-header-1590514\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>You\u2019d typically use the volume-based version of the formula: <span class=\"math-inline\" data-math=\"V = (V_m \\cdot bP) \/ (1 + bP)\" data-index-in-node=\"134\">V = (V<sub>m<\/sub> \u00b7 bP) \/ (1 + bP)<\/span>, where <span class=\"math-inline\" data-math=\"V_m\" data-index-in-node=\"171\">V<sub>m<\/sub><\/span>\u00a0is the volume of gas needed to form a complete monolayer.<\/p>\n\t\t<\/div> <!-- Close content div. -->\n\t<\/div> <!-- Close collapse div. -->\n<\/div> <!-- Close card div. -->\n<\/div>\n<\/div>\n\n","protected":false},"excerpt":{"rendered":"<p>Langmuir adsorption isotherm For IIT JAM is a mathematical model used to describe the adsorption of molecules onto a surface. It&#8217;s a fundamental concept in physical chemistry and is often tested in IIT JAM and CSIR NET exams. Understanding Langmuir adsorption isotherm is crucial for students preparing for competitive exams.<\/p>\n","protected":false},"author":12,"featured_media":12536,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","rank_math_seo_score":88},"categories":[23],"tags":[2923,7396,7397,7398,7399,2922],"class_list":["post-12537","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-iit-jam","tag-competitive-exams","tag-langmuir-adsorption-isotherm-for-iit-jam","tag-langmuir-adsorption-isotherm-for-iit-jam-notes","tag-langmuir-adsorption-isotherm-for-iit-jam-questions","tag-langmuir-adsorption-isotherm-for-iit-jam-study-material","tag-vedprep","entry","has-media"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12537","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/comments?post=12537"}],"version-history":[{"count":7,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12537\/revisions"}],"predecessor-version":[{"id":15915,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12537\/revisions\/15915"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media\/12536"}],"wp:attachment":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media?parent=12537"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/categories?post=12537"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/tags?post=12537"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}