{"id":211497,"date":"2025-05-03T21:50:57","date_gmt":"2025-05-03T21:50:57","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=211497"},"modified":"2025-05-03T21:51:00","modified_gmt":"2025-05-03T21:51:00","slug":"one-of-the-challenges-of-plotting-an-r-407c-system-on-a-pressure-enthalpy-chart-is-that-this-refrigerant","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/03\/one-of-the-challenges-of-plotting-an-r-407c-system-on-a-pressure-enthalpy-chart-is-that-this-refrigerant\/","title":{"rendered":"One of the challenges of plotting an R-407C system on a pressure\/enthalpy chart is that this refrigerant"},"content":{"rendered":"\n<p>One of the challenges of plotting an R-407C system on a pressure\/enthalpy chart is that this refrigerant<\/p>\n\n\n\n<p>A. is a single-compound refrigerant with one pressure for each temperature.<br>B. has a significant temperature glide.<br>C. is a binary blend of R-32 and R-125, making it unstable.<br>D. is easily mistaken for R-134a and R-410A.<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>The correct answer is <strong>B. has a significant temperature glide<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>R-407C is a refrigerant blend that consists of three components: R-32 (difluoromethane), R-125 (pentafluoroethane), and R-134a (1,1,1,2-tetrafluoroethane). Unlike single-component refrigerants, which typically exhibit a constant temperature at a given pressure (a characteristic of pure refrigerants), R-407C is a <strong>zeotropic mixture<\/strong>, meaning that it has a significant temperature glide.<\/p>\n\n\n\n<p><strong>Temperature glide<\/strong> refers to the phenomenon where the temperature of the refrigerant mixture changes as it evaporates or condenses at a constant pressure. This occurs because the components of the mixture have different boiling points, leading to different rates of evaporation and condensation at the same pressure. As a result, when plotting R-407C on a pressure\/enthalpy chart, the line representing the phase change (evaporation or condensation) is not vertical but has a slope, indicating that the temperature changes over the course of the phase transition.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Why the other options are incorrect:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>A. is a single-compound refrigerant with one pressure for each temperature:<\/strong> This is incorrect because R-407C is not a single-compound refrigerant. It is a blend of multiple components with varying boiling points, leading to a temperature glide.<\/li>\n\n\n\n<li><strong>C. is a binary blend of R-32 and R-125, making it unstable:<\/strong> While R-407C is indeed a blend of R-32 and R-125, it is not a binary blend; it also contains R-134a. Moreover, R-407C is not inherently unstable. The instability of a refrigerant typically refers to chemical instability under certain conditions, which is not a characteristic of R-407C.<\/li>\n\n\n\n<li><strong>D. is easily mistaken for R-134a and R-410A:<\/strong> While R-407C may share some similarities with R-134a and R-410A in terms of performance and applications, it is a distinct blend and is not typically mistaken for these refrigerants when proper identification is made.<\/li>\n<\/ul>\n\n\n\n<p>Thus, the key challenge when plotting R-407C on a pressure\/enthalpy chart is its <strong>significant temperature glide<\/strong>, which makes it more complex to represent compared to single-component refrigerants.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>One of the challenges of plotting an R-407C system on a pressure\/enthalpy chart is that this refrigerant A. is a single-compound refrigerant with one pressure for each temperature.B. has a significant temperature glide.C. is a binary blend of R-32 and R-125, making it unstable.D. is easily mistaken for R-134a and R-410A. The correct answer and [&hellip;]<\/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-211497","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/211497","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=211497"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/211497\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=211497"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=211497"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=211497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}