{"id":244141,"date":"2025-07-04T19:35:17","date_gmt":"2025-07-04T19:35:17","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=244141"},"modified":"2025-07-04T19:35:19","modified_gmt":"2025-07-04T19:35:19","slug":"coz-25-atm-and-65-pc-solid-liquid-0-l-5-11-1-0-liquid-gas-solid-gas","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/04\/coz-25-atm-and-65-pc-solid-liquid-0-l-5-11-1-0-liquid-gas-solid-gas\/","title":{"rendered":"COz 25 atm and -65 PC? solid liquid 0 L 5.11 1.0 liquid gas solid gas"},"content":{"rendered":"\n

COz 25 atm and -65 PC? solid liquid 0 L 5.11 1.0 liquid gas solid gas Starting from the same point; 25 atm and ~65 ‘C, what phase change would eventually result from a decrease in pressure? -78.5 556.4 Temperature (‘C) 31,1 melting sublimation deposition freezing vaporization condensation
Consider the phase diagram for carbon dioxide: 73.0 In what phase is COz 25 atm and -65 PC? solid liquid 0 L 5.11 1.0 liquid gas solid gas Starting from the same point; 25 atm and ~65 ‘C, what phase change would eventually result from a decrease in pressure? -78.5 556.4 Temperature (‘C) 31,1 melting sublimation deposition freezing vaporization condensation<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

Here are the correct answers and a detailed explanation based on the provided phase diagram for carbon dioxide.<\/p>\n\n\n\n

First question:<\/strong> In what phase is CO\u2082 at 25 atm and \u201365 \u00b0C?
Correct Answer:<\/strong> solid<\/p>\n\n\n\n

Second question:<\/strong> Starting from the same point, 25 atm and \u201365 \u00b0C, what phase change would eventually result from a decrease in pressure?
Correct Answer:<\/strong> sublimation<\/p>\n\n\n\n

\n\n\n\n

Explanation<\/strong><\/h3>\n\n\n\n

Part 1: Determining the Initial Phase<\/strong><\/p>\n\n\n\n

To find the phase of carbon dioxide (CO\u2082) at a specific pressure and temperature, you must locate that point on the phase diagram. The diagram shows pressure on the vertical (y) axis and temperature on the horizontal (x) axis.<\/p>\n\n\n\n

    \n
  1. Locate the temperature:<\/strong>\u00a0Find \u201365 \u00b0C on the x-axis. This temperature is to the left of the triple point temperature (\u201356.4 \u00b0C) but to the right of the normal sublimation point (\u201378.5 \u00b0C).<\/li>\n\n\n\n
  2. Locate the pressure:<\/strong>\u00a0Find 25 atm on the y-axis. This pressure is well above the triple point pressure (5.11 atm) and below the critical pressure (73.0 atm).<\/li>\n\n\n\n
  3. Find the intersection:<\/strong>\u00a0Trace a vertical line upwards from \u201365 \u00b0C and a horizontal line across from 25 atm. The point where these two lines intersect falls squarely within the region labeled\u00a0solid<\/strong>\u00a0(the blue-shaded area). Therefore, at 25 atm and \u201365 \u00b0C, CO\u2082 is in the solid phase.<\/li>\n<\/ol>\n\n\n\n

    Part 2: Identifying the Phase Change<\/strong><\/p>\n\n\n\n

    The second question describes a process starting from the point identified above (solid CO\u2082 at 25 atm and \u201365 \u00b0C) and then decreasing the pressure while the temperature remains constant at \u201365 \u00b0C.<\/p>\n\n\n\n

      \n
    1. Trace the process on the diagram:<\/strong>\u00a0A decrease in pressure at a constant temperature is represented by moving vertically downwards from the starting point on the phase diagram.<\/li>\n\n\n\n
    2. Identify the phase transition:<\/strong>\u00a0Starting at (\u201365 \u00b0C, 25 atm) in the solid region, moving straight down means crossing the boundary line that separates the solid phase from the gas phase.<\/li>\n\n\n\n
    3. Name the phase change:<\/strong>\u00a0The direct transition from a solid to a gas is known as\u00a0sublimation<\/strong>. Because the temperature (\u201365 \u00b0C) is below the triple point temperature (\u201356.4 \u00b0C), the CO\u2082 bypasses the liquid phase entirely. If the temperature were above \u201356.4 \u00b0C, a decrease in pressure might cause melting (solid to liquid) followed by vaporization (liquid to gas). However, at \u201365 \u00b0C, only sublimation is possible as the pressure is lowered.<\/li>\n<\/ol>\n\n\n\n
      \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

      COz 25 atm and -65 PC? solid liquid 0 L 5.11 1.0 liquid gas solid gas Starting from the same point; 25 atm and ~65 ‘C, what phase change would eventually result from a decrease in pressure? -78.5 556.4 Temperature (‘C) 31,1 melting sublimation deposition freezing vaporization condensationConsider the phase diagram for carbon dioxide: 73.0 […]<\/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-244141","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/244141","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=244141"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/244141\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=244141"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=244141"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=244141"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}