{"id":12539,"date":"2026-05-12T15:13:02","date_gmt":"2026-05-12T15:13:02","guid":{"rendered":"https:\/\/www.vedprep.com\/exams\/?p=12539"},"modified":"2026-05-12T15:13:02","modified_gmt":"2026-05-12T15:13:02","slug":"freundlich-adsorption-isotherm","status":"publish","type":"post","link":"https:\/\/www.vedprep.com\/exams\/iit-jam\/freundlich-adsorption-isotherm\/","title":{"rendered":"Freundlich Adsorption Isotherm For IIT JAM 2027: Master Tips"},"content":{"rendered":"<p>The Freundlich adsorption isotherm is a mathematical model describing the adsorption of gases onto solid surfaces, widely used in IIT JAM and CSIR NET chemistry.<\/p>\n<h2><strong>Freundlich adsorption isotherm For IIT JAM<\/strong><\/h2>\n<p data-path-to-node=\"1\">If you\u2019re diving into <a href=\"https:\/\/jam2026.iitb.ac.in\/files\/syllabus_CY.pdf\" rel=\"nofollow noopener\" target=\"_blank\"><strong>physical chemistry for IIT JAM<\/strong><\/a>, you already know that surface chemistry is one of those high-yield areas where you can score some relatively easy marks if your basics are solid. Within that, the <b data-path-to-node=\"1\" data-index-in-node=\"217\">Freundlich adsorption isotherm<\/b> is a total staple. It shows up in the thermodynamics and kinetics section of the JAM syllabus, and honestly, if you&#8217;re also eyeing CSIR NET or GATE down the road, you\u2019re going to see this concept over and over again.<\/p>\n<p data-path-to-node=\"2\">To really get under the hood of this topic, most of us end up leaning on the classics. Atkins is great for the heavy lifting on principles, and Levine is a lifesaver when you need a deep dive into the math. At <a href=\"https:\/\/www.vedprep.com\/online-courses\"><strong>VedPrep<\/strong><\/a>, we\u2019ve noticed that students who master this early have a much smoother ride when they hit the more complex industrial applications later on.<\/p>\n<p>For in-depth study, students can refer to standard textbooks such as the following:<\/p>\n<ul>\n<li>Atkins, Physical Chemistry, 10th Edition\u2014a comprehensive resource that covers the principles of physical chemistry, including adsorption isotherms.<\/li>\n<li>Levine, Physical Chemistry, 6th Edition\u2014another widely used textbook that provides detailed explanations of surface chemistry and adsorption phenomena.<\/li>\n<\/ul>\n<h2 data-path-to-node=\"4\"><strong>Freundlich Adsorption Isotherm: Definition and Mathematical Expression<\/strong><\/h2>\n<p data-path-to-node=\"5\">Let\u2019s keep it simple. An adsorption isotherm is basically just a graph. It shows how much gas or liquid gets &#8220;stuck&#8221; to a solid surface as you change the pressure, all while keeping the temperature steady. The <b data-path-to-node=\"5\" data-index-in-node=\"210\">Freundlich adsorption isotherm<\/b> is an empirical model\u2014which is just a fancy way of saying it\u2019s based on what scientists actually saw happening in the lab rather than just a pure theory.<\/p>\n<p data-path-to-node=\"6\">The math looks like this:<\/p>\n<p data-path-to-node=\"6\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-15933 aligncenter\" src=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Freundlich-adsorption-isotherm.png\" alt=\"Freundlich adsorption isotherm\" width=\"186\" height=\"97\" \/><\/p>\n<p data-path-to-node=\"8\">Here\u2019s the breakdown of what those letters actually mean:<\/p>\n<ul data-path-to-node=\"9\">\n<li>\n<p data-path-to-node=\"9,0,0\"><b data-path-to-node=\"9,0,0\" data-index-in-node=\"0\"><span class=\"math-inline\" data-math=\"x\" data-index-in-node=\"0\">x<\/span><\/b>: The amount of stuff (adsorbate) that\u2019s stuck.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"9,1,0\"><b data-path-to-node=\"9,1,0\" data-index-in-node=\"0\"><span class=\"math-inline\" data-math=\"m\" data-index-in-node=\"0\">m<\/span><\/b>: The mass of the solid (adsorbent) doing the sticking.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"9,2,0\"><b data-path-to-node=\"9,2,0\" data-index-in-node=\"0\"><span class=\"math-inline\" data-math=\"P\" data-index-in-node=\"0\">P<\/span><\/b>: The pressure of the gas.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"9,3,0\"><b data-path-to-node=\"9,3,0\" data-index-in-node=\"0\"><span class=\"math-inline\" data-math=\"K\" data-index-in-node=\"0\">K<\/span> and <span class=\"math-inline\" data-math=\"n\" data-index-in-node=\"6\">n<\/span><\/b>: These are constants. They change depending on the materials you&#8217;re using.<\/p>\n<\/li>\n<\/ul>\n<p data-path-to-node=\"10\">Basically, as you crank up the pressure, more gas molecules get forced onto the surface, so <span class=\"math-inline\" data-math=\"\\frac{x}{m}\" data-index-in-node=\"92\">x\/m<\/span>\u00a0goes up. Think of it like a sponge\u2014the harder you press a damp sponge against a spill, the more it\u2019s going to soak up until it hits a limit.<\/p>\n<h2 data-path-to-node=\"12\"><strong>Freundlich Adsorption Isotherm For IIT JAM: Key Features and Assumptions<\/strong><\/h2>\n<p data-path-to-node=\"13\">The big thing to remember for JAM is that Freundlich assumes a <b data-path-to-node=\"13\" data-index-in-node=\"63\">heterogeneous surface<\/b>. Imagine a rocky mountain face instead of a smooth glass table. Some spots on that mountain are perfect for a hiker to grab onto (high energy sites), while others are slippery and useless (low energy sites).<\/p>\n<p data-path-to-node=\"14\">Key things to keep in mind:<\/p>\n<ul data-path-to-node=\"15\">\n<li>\n<p data-path-to-node=\"15,0,0\"><b data-path-to-node=\"15,0,0\" data-index-in-node=\"0\">It\u2019s not ideal:<\/b> It doesn&#8217;t pretend every spot on the surface is the same.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"15,1,0\"><b data-path-to-node=\"15,1,0\" data-index-in-node=\"0\">Heterogeneous surface:<\/b> Adsorption happens on different types of sites with different energies.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"15,2,0\"><b data-path-to-node=\"15,2,0\" data-index-in-node=\"0\">Finite capacity:<\/b> It acknowledges that eventually, you can&#8217;t just keep adding more and more stuff.<\/p>\n<\/li>\n<\/ul>\n<p data-path-to-node=\"16\">While models like the Langmuir isotherm assume everything is perfect and uniform, the <b data-path-to-node=\"16\" data-index-in-node=\"86\">Freundlich adsorption isotherm<\/b> is more like the &#8220;real world&#8221; version that accounts for all the bumps and imperfections on a surface.<\/p>\n<h2 data-path-to-node=\"18\"><strong>Freundlich<\/strong> Adsorption Isotherm: Worked Example For CSIR NET<\/h2>\n<p data-path-to-node=\"20\">Imagine you\u2019re given a set of data where the amount of gas adsorbed triples when the pressure is increased by a factor of nine. You can use the log version of the formula to find <span class=\"math-inline\" data-math=\"n\" data-index-in-node=\"179\">n<\/span>:<\/p>\n<p data-path-to-node=\"20\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-15934 aligncenter\" src=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Freundlich-Adsorption-Isotherm-Worked-Example-300x78.png\" alt=\"Freundlich Adsorption Isotherm Worked Example\" width=\"300\" height=\"78\" srcset=\"https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Freundlich-Adsorption-Isotherm-Worked-Example-300x78.png 300w, https:\/\/www.vedprep.com\/exams\/wp-content\/uploads\/Freundlich-Adsorption-Isotherm-Worked-Example.png 336w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p data-path-to-node=\"20\">By plotting <span class=\"math-inline\" data-math=\"\\log(\\frac{x}{m})\" data-index-in-node=\"13\">x\/m<\/span> against <span class=\"math-inline\" data-math=\"\\log P\" data-index-in-node=\"39\">log P<\/span>, you get a straight line. The slope of that line is your <span class=\"math-inline\" data-math=\"\\frac{1}{n}\" data-index-in-node=\"103\">1\/n<\/span>. If you&#8217;re stuck on these types of calculations, don&#8217;t sweat it\u2014we see JAM aspirants trip up on the log math all the time at <strong>VedPrep<\/strong>, but it&#8217;s just a bit of practice.<\/p>\n<h2 data-path-to-node=\"24\"><strong>Misconceptions in Freundlich Adsorption Isotherm For IIT JAM<\/strong><\/h2>\n<p data-path-to-node=\"25\">A huge mistake students make is thinking this is an &#8220;ideal&#8221; model. It\u2019s definitely not. Ideal models assume the surface is as flat and predictable as a fresh sheet of ice. But the <b data-path-to-node=\"25\" data-index-in-node=\"180\">Freundlich adsorption isotherm<\/b> knows better\u2014it assumes the surface is messy and varied (heterogeneous).<\/p>\n<p data-path-to-node=\"26\">Because the surface sites have different &#8220;clinginess&#8221; (energies), the molecules don&#8217;t spread out perfectly. This is why the equation doesn&#8217;t show a simple 1:1 direct proportionality. It\u2019s a bit more nuanced than that, which makes it way more accurate for most actual chemistry experiments you\u2019ll run into.<\/p>\n<h2 data-path-to-node=\"28\"><strong>Application of Freundlich Adsorption Isotherm in Real-World Scenarios<\/strong><\/h2>\n<p data-path-to-node=\"29\">Why do we care about this? Because it\u2019s how we clean up the planet.<\/p>\n<ul data-path-to-node=\"30\">\n<li>\n<p data-path-to-node=\"30,0,0\"><b data-path-to-node=\"30,0,0\" data-index-in-node=\"0\">Cleaning Water:<\/b> If you&#8217;ve ever used a charcoal water filter, you&#8217;ve used this principle. The activated carbon pulls out impurities from the water based on these isotherms.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"30,1,0\"><b data-path-to-node=\"30,1,0\" data-index-in-node=\"0\">Industrial Cleanup:<\/b> Factories use this to design systems that scrub toxic gases out of their exhaust before it hits the atmosphere.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"30,2,0\"><b data-path-to-node=\"30,2,0\" data-index-in-node=\"0\">Catalysis:<\/b> It helps chemists understand how reactants sit on a catalyst to make a reaction go faster.<\/p>\n<\/li>\n<\/ul>\n<p><b data-path-to-node=\"31\" data-index-in-node=\"0\">A quick (fictional) example:<\/b> Imagine a small town&#8217;s water supply gets contaminated with a specific dye from a nearby factory. Engineers don&#8217;t just guess how much carbon they need to clean it. They use the <b data-path-to-node=\"31\" data-index-in-node=\"205\">Freundlich adsorption isotherm<\/b> to calculate exactly how much adsorbent (the carbon) is needed to &#8220;trap&#8221; the <span class=\"math-inline\" data-math=\"x\" data-index-in-node=\"313\">$x$<\/span> amount of dye molecules at a certain concentration. Without this math, they&#8217;d either waste money on too much carbon or, worse, leave the water messy.<\/p>\n<h2 data-path-to-node=\"33\"><strong>Exam Strategy for Freundlich Adsorption Isotherm For IIT JAM<\/strong><\/h2>\n<p data-path-to-node=\"34\">When you&#8217;re sitting in that exam hall, the questions usually boil down to three things: the equation, the graph, or the limitations.<\/p>\n<ol start=\"1\" data-path-to-node=\"35\">\n<li>\n<p data-path-to-node=\"35,0,0\"><b data-path-to-node=\"35,0,0\" data-index-in-node=\"0\">Memorize the log form:<\/b> It\u2019s almost always easier to solve problems using <span class=\"math-inline\" data-math=\"\\log(\\frac{x}{m}) = \\log K + \\frac{1}{n} \\log P\" data-index-in-node=\"73\">log(x\/m) = log K + 1\/n log P<\/span>.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"35,1,0\"><b data-path-to-node=\"35,1,0\" data-index-in-node=\"0\">Know the constants:<\/b> Understand what happens if <span class=\"math-inline\" data-math=\"n = 1\" data-index-in-node=\"47\">n = 1<\/span> or if <span class=\"math-inline\" data-math=\"n\" data-index-in-node=\"59\">n<\/span>\u00a0is very large.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"35,2,0\"><b data-path-to-node=\"35,2,0\" data-index-in-node=\"0\">Practice the graphs:<\/b> Being able to look at a curve and know if it\u2019s Freundlich or Langmuir is a superpower.<\/p>\n<\/li>\n<\/ol>\n<p data-path-to-node=\"36\">At <a href=\"https:\/\/www.vedprep.com\/online-courses\/iit-jam\"><strong>VedPrep<\/strong><\/a>, we usually suggest our students practice at least 10-15 different variations of these problems. Once you see the pattern, it\u2019s hard to forget.<\/p>\n<h2 data-path-to-node=\"38\"><strong>Key Limitations and Criticisms of Freundlich Adsorption Isotherm<\/strong><\/h2>\n<p data-path-to-node=\"39\">As helpful as it is, this model isn&#8217;t perfect.<\/p>\n<ul data-path-to-node=\"40\">\n<li>\n<p data-path-to-node=\"40,0,0\"><b data-path-to-node=\"40,0,0\" data-index-in-node=\"0\">No Surface Diffusion:<\/b> It ignores the fact that molecules might slide around on the surface after they land.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"40,1,0\"><b data-path-to-node=\"40,1,0\" data-index-in-node=\"0\">Low Pressure Failure:<\/b> If the pressure is super low, the math starts to fall apart and doesn&#8217;t match what we see in real life.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"40,2,0\"><b data-path-to-node=\"40,2,0\" data-index-in-node=\"0\">Temperature Issues:<\/b> It\u2019s mostly an &#8220;at one temperature&#8221; deal. If you start heating things up, the Freundlich model doesn&#8217;t stay very accurate.<\/p>\n<\/li>\n<li>\n<p data-path-to-node=\"40,3,0\"><b data-path-to-node=\"40,3,0\" data-index-in-node=\"0\">No Real Theory:<\/b> Since it&#8217;s empirical (based on observation), it doesn&#8217;t really explain <i data-path-to-node=\"40,3,0\" data-index-in-node=\"87\">why<\/i> the molecules are sticking\u2014it just tells you that they <i data-path-to-node=\"40,3,0\" data-index-in-node=\"146\">are<\/i>.<\/p>\n<\/li>\n<\/ul>\n<section>\n<h2>Conclusion<\/h2>\n<p>The <b data-path-to-node=\"0\" data-index-in-node=\"24\">Freundlich adsorption isotherm<\/b> is one of those concepts that might look a bit intimidating on paper with its logs and exponents, but it\u2019s actually pretty grounded in how the real world works. For any IIT JAM aspirant, mastering this isn&#8217;t just about ticking off a box in the syllabus\u2014it\u2019s about understanding the &#8220;messy&#8221; side of chemistry where surfaces aren&#8217;t perfect and reactions don&#8217;t always follow the ideal rules.<\/p>\n<p>To know more in detail from our expert faculty, watch our YouTube Video:<\/p>\n<p class=\"responsive-video-wrap clr\"><iframe title=\"Surface Chemistry | Freundlich Adsorption Isotherm | CSIR NET| GATE| IIT JAM| DU| BHU| CHEM ACADEMY\" width=\"1200\" height=\"675\" src=\"https:\/\/www.youtube.com\/embed\/kFrE_9ibjck?feature=oembed\" 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<h2>Frequently Asked Questions<\/h2>\n<\/section>\n<style>#sp-ea-15938 .spcollapsing { height: 0; overflow: hidden; transition-property: height;transition-duration: 300ms;}#sp-ea-15938.sp-easy-accordion>.sp-ea-single {margin-bottom: 10px; border: 1px solid #e2e2e2; }#sp-ea-15938.sp-easy-accordion>.sp-ea-single>.ea-header a {color: #444;}#sp-ea-15938.sp-easy-accordion>.sp-ea-single>.sp-collapse>.ea-body {background: #fff; color: #444;}#sp-ea-15938.sp-easy-accordion>.sp-ea-single {background: #eee;}#sp-ea-15938.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-1778598271\">\n<div id=\"sp-ea-15938\" 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-159380\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159380\" aria-controls=\"collapse159380\" 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 is the Freundlich adsorption 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 collapsed show\" id=\"collapse159380\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159380\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>It\u2019s an empirical equation that describes how the amount of gas adsorbed by a solid varies with pressure at a constant temperature.<\/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-159381\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159381\" aria-controls=\"collapse159381\" 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 standard mathematical formula for it?\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=\"collapse159381\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159381\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>The formula is <span class=\"math-inline\" data-math=\"\\frac{x}{m} = Kp^{1\/n}\" data-index-in-node=\"68\">x\/m = Kp<sup>1\/n<\/sup><\/span>, where <span class=\"math-inline\" data-math=\"x\/m\" data-index-in-node=\"98\">$x\/m$<\/span> is the extent of adsorption, <span class=\"math-inline\" data-math=\"P\" data-index-in-node=\"131\">P<\/span>\u00a0is pressure, and <span class=\"math-inline\" data-math=\"K\" data-index-in-node=\"150\">K<\/span> and <span class=\"math-inline\" data-math=\"n\" data-index-in-node=\"156\">n<\/span>\u00a0are constants.<\/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-159382\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159382\" aria-controls=\"collapse159382\" 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 \"empirical\" mean in this context?\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=\"collapse159382\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159382\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>It means the model is based on experimental observations and data rather than being derived from a theoretical first principle.<\/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-159383\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159383\" aria-controls=\"collapse159383\" 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 physical significance of x and m?\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=\"collapse159383\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159383\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p><span class=\"math-inline\" data-math=\"x\" data-index-in-node=\"49\">x<\/span> represents the mass of the adsorbate (the gas), and <span class=\"math-inline\" data-math=\"m\" data-index-in-node=\"103\">m<\/span>\u00a0is the mass of the adsorbent (the solid 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-159384\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159384\" aria-controls=\"collapse159384\" 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 slope of the Freundlich plot 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=\"collapse159384\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159384\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>In a plot of <span class=\"math-inline\" data-math=\"\\log(x\/m)\" data-index-in-node=\"70\">log(x\/m)<\/span>\u00a0vs <span class=\"math-inline\" data-math=\"\\log P\" data-index-in-node=\"83\">log P<\/span>, the slope is equal to <span class=\"math-inline\" data-math=\"1\/n\" data-index-in-node=\"113\">1\/n<\/span>.<\/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-159385\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159385\" aria-controls=\"collapse159385\" 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 intercept represent in the log plot?\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=\"collapse159385\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159385\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>The intercept on the y-axis gives you the value of <span class=\"math-inline\" data-math=\"\\log K\" data-index-in-node=\"105\">log K<\/span>.<\/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-159386\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159386\" aria-controls=\"collapse159386\" 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 this isotherm used 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=\"collapse159386\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159386\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>While it can apply to both, it is most commonly used to describe physical adsorption (physisorption) on rough surfaces.<\/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-159387\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159387\" aria-controls=\"collapse159387\" 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 an \"isotherm\" anyway?\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=\"collapse159387\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159387\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>It\u2019s a curve that shows the relationship between two variables (like pressure and adsorption) while the temperature stays exactly the same.<\/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-159388\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159388\" aria-controls=\"collapse159388\" 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 this isotherm work at very high pressures?\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=\"collapse159388\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159388\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>No. A major mistake is applying it to high-pressure scenarios where adsorption usually becomes independent of pressure (reaches saturation).<\/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-159389\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse159389\" aria-controls=\"collapse159389\" 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> Do I need to worry about units?\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=\"collapse159389\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-159389\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Yes. Always check if the pressure is in atm, bar, or torr, as this will change the value of <span class=\"math-inline\" data-math=\"K\" data-index-in-node=\"128\">K<\/span>.<\/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-1593810\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1593810\" aria-controls=\"collapse1593810\" 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=\"collapse1593810\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-1593810\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>At very low pressure, <span class=\"math-inline\" data-math=\"1\/n\" data-index-in-node=\"77\">$1\/n$<\/span> often approaches 1, meaning adsorption is directly proportional to pressure (<span class=\"math-inline\" data-math=\"\\frac{x}{m} \\propto P^1\" data-index-in-node=\"158\">x\/m \u221d P<sup>1<\/sup><\/span>).<\/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-1593811\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1593811\" aria-controls=\"collapse1593811\" 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 does temperature affect the constants K and n?\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=\"collapse1593811\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-1593811\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Since adsorption is generally exothermic, as temperature increases, the extent of adsorption decreases, which changes these constant values.<\/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-1593812\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1593812\" aria-controls=\"collapse1593812\" 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 a \"heterogeneous surface\" in Freundlich theory?\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=\"collapse1593812\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-1593812\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>It means the surface has sites with different binding energies. Some spots are \"stickier\" than others.<\/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-1593813\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1593813\" aria-controls=\"collapse1593813\" 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 does it differ from the Langmuir 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=\"collapse1593813\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-1593813\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>Langmuir assumes a perfectly flat, uniform surface where every spot is the same. Freundlich assumes the surface is bumpy and varied.<\/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-1593814\" role=\"button\" data-sptoggle=\"spcollapse\" data-sptarget=\"#collapse1593814\" aria-controls=\"collapse1593814\" 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 significance of the value of n?\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=\"collapse1593814\" data-parent=\"#sp-ea-15938\" role=\"region\" aria-labelledby=\"ea-header-1593814\">  <!-- Content div. -->\n\t\t<div class=\"ea-body\">\n\t\t<p>It\u2019s a measure of the intensity of adsorption. Usually, if <span class=\"math-inline\" data-math=\"n &gt; 1\" data-index-in-node=\"107\">n &gt; 1<\/span>, it indicates favorable adsorption.<\/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>The Freundlich adsorption isotherm is a mathematical model describing the adsorption of gases onto solid surfaces, widely used in IIT JAM and CSIR NET chemistry. This topic is covered under the official CSIR NET \/ NTA syllabus unit of Physical Chemistry, specifically in the section on Surface Chemistry or Adsorption. Students preparing for IIT JAM, CSIR NET, and GATE exams need to focus on this area.<\/p>\n","protected":false},"author":12,"featured_media":12538,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","rank_math_seo_score":88},"categories":[23],"tags":[2923,7400,7401,7402,7403,2922],"class_list":["post-12539","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-iit-jam","tag-competitive-exams","tag-freundlich-adsorption-isotherm-for-iit-jam","tag-freundlich-adsorption-isotherm-for-iit-jam-notes","tag-freundlich-adsorption-isotherm-for-iit-jam-questions","tag-freundlich-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\/12539","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=12539"}],"version-history":[{"count":5,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12539\/revisions"}],"predecessor-version":[{"id":15943,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/posts\/12539\/revisions\/15943"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media\/12538"}],"wp:attachment":[{"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/media?parent=12539"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/categories?post=12539"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vedprep.com\/exams\/wp-json\/wp\/v2\/tags?post=12539"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}