{"id":2716,"date":"2016-08-24T17:21:53","date_gmt":"2016-08-24T17:21:53","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/?post_type=chapter&#038;p=2716"},"modified":"2016-08-26T18:22:29","modified_gmt":"2016-08-26T18:22:29","slug":"physical-properties-of-water","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/chapter\/physical-properties-of-water\/","title":{"raw":"Physical Properties of Water","rendered":"Physical Properties of Water"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Objectives<\/h3>\r\n<div class=\"x-ck12-data-objectives\">\r\n<ul id=\"x-ck12-NGQzYjBkZWMxMmUyYWJkYTJiMjVmNDczOGNkZTY2OWE.-jv6\">\r\n \t<li style=\"text-align: left;\">Define surface tension.<\/li>\r\n \t<li style=\"text-align: left;\">Define vapor pressure.<\/li>\r\n \t<li style=\"text-align: left;\">Explain the physical\u00a0properties of water in terms of hydrogen bonding.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox examples\">\r\n<h3>What is this pan used for?<\/h3>\r\n[caption id=\"\" align=\"alignleft\" width=\"239\"]<img class=\"\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212326\/20140811155539189562.jpeg\" alt=\"An evaporation pan is used to measure the rate at which water evaporates\" width=\"239\" height=\"179\" \/> Evaporation pan. Courtesy of <a href=\"http:\/\/commons.wikimedia.org\/wiki\/File:Evaporation_pan.jpg\">NOAA<\/a>.[\/caption]\r\n<p id=\"x-ck12-MTQ2NmIzNTQ2MWJlZmRhNTEzNTE1NzNiYTQ1NjIyYjY.-jpx\">\u00a0Water loss to the atmosphere is a significant problem in many parts of the world.\u00a0 When water supplies are low, anything that can be done to decrease water loss is important for farmers.\u00a0 An evaporation pan (seen above) can be used to measure how fast water evaporates in a given location.\u00a0 This information can be used as part of projects to develop ways to cut down on evaporation and increase the amount of usable water in a region.<\/p>\r\n&nbsp;\r\n\r\n<\/div>\r\n<h2>Properties of Water<\/h2>\r\n<p id=\"x-ck12-YzVhMjY3NmNiYzJhYzhlYTkxN2JiMWQyYWY2ZmE2YTY.-ykp\">Compared to other molecular compounds of relatively low molar mass, ice melts at a very high temperature.\u00a0 A great deal of energy is required to break apart the hydrogen-bonded network of ice and return it to the liquid state.\u00a0 Likewise, the boiling point of water is very high.\u00a0 Most molecular compounds of similar molar mass are gases at room temperature.<\/p>\r\n\r\n<h2>Surface Tension<\/h2>\r\n<p id=\"x-ck12-ZjkyMjcxNzI3YmI5OTBiNWNkZDI2MWM3M2U2NGYzNDM.-hld\">Water has a high <strong> surface <\/strong> <strong> tension <\/strong> (attraction between molecules at the surface of a liquid) because of its hydrogen bonding.\u00a0 Liquids that cannot hydrogen bond do not exhibit nearly as much surface tension.\u00a0 Surface tension can be seen by the curved meniscus that forms when water is in a thin column such as a graduated cylinder or a buret.<\/p>\r\n\r\n<div id=\"x-ck12-ZjA1MTIwNzk4OGU2YmNhNDZhNmE4NWY3ODRkNTNmNmE.-dwb\" class=\"x-ck12-img-thumbnail x-ck12-nofloat\">\r\n\r\n[caption id=\"\" align=\"alignright\" width=\"128\"]<img id=\"x-ck12-OTgwNDUtMTM2NzI1ODE3MS0xMS02MS1zaHV0dGVyc3RvY2tfMTQ2MjIxOQ..\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212328\/20140811155539562459.jpeg\" alt=\"Water forms a meniscus because of the surface tension generated by water's hydrogen bonding\" width=\"128\" height=\"192\" longdesc=\"The%20meniscus%20of%20water%20in%20a%20graduated%20cylinder%20forms%20because%20of%20water%E2%80%99s%20hydrogen%20bonding.\" \/> Figure 1. The meniscus of water in a graduated cylinder forms because of water\u2019s hydrogen bonding. Image by Peter Witkop, 2014. http:\/\/www.shutterstock.com.[\/caption]\r\n\r\n&nbsp;\r\n\r\n<\/div>\r\n<h2>Vapor Pressure<\/h2>\r\n<p id=\"x-ck12-Y2FlODU5YTMwMTBiMTZjOWNkMGMwMTEzYTBmYjFmYWY.-qzt\">The <strong> vapor <\/strong> <strong> pressure <\/strong> of a liquid is the pressure of the vapor produced by evaporation of a liquid or solid above the liquid or solid in a closed container. The hydrogen bonding between liquid water molecules explains why water has an unusually low vapor pressure.\u00a0 Relatively few molecules of water are capable of escaping the surface of the liquid and enter the vapor phase.\u00a0 Evaporation is slow and thus the vapor exerts a low pressure in a closed container.\u00a0 Low vapor pressure is an important physical property of water, since lakes, oceans, and other large bodies of water would all tend to evaporate much more quickly otherwise.<\/p>\r\n<p id=\"x-ck12-M2I3N2Q4OGI4NmYyM2IzZjA4OWFiMzgwYTc0YzZkNzQ.-ynd\">Vapor pressure is influenced by temperature. As the temperature increases, more molecules are released from the surface of the liquid.\u00a0 This increases movement above the liquid surface, increasing the pressure in the vapor stage. \u00a0The image below\u00a0illustrates the effect of temperature on vapor pressure.<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"250\"]<img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212329\/20140811155539711545.png\" alt=\"As temperature increases, vapor pressure increases as well\" width=\"250\" height=\"260\" \/> Figure 2. From Garnix\/Wikipedia. http:\/\/commons.wikimedia.org\/wiki\/File:Dampfdruck05.png.[\/caption]\r\n\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Summary<\/h3>\r\n<ul id=\"x-ck12-NWQ4NDYzYThhYzQxZTBlYzNhODg2ZmI5YmFiMTAzN2U.-6lv\">\r\n \t<li>Water has high surface tension because of extensive hydrogen bonding.<\/li>\r\n \t<li>The vapor pressure of water is low due to hydrogen bonding.<\/li>\r\n \t<li>Vapor pressure increases as temperature increases.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Practice<\/h3>\r\nUse the link below to answer the following questions:\r\n<p id=\"x-ck12-MGQ0N2YyZjhkOTdjY2Y1OGJlY2ZmYzlhZWU2MTUyMjg.-ukv\"><a href=\"http:\/\/science.howstuffworks.com\/environmental\/earth\/geophysics\/h2o7.htm%20\"> http:\/\/science.howstuffworks.com\/environmental\/earth\/geophysics\/h2o7.htm <\/a><\/p>\r\n\r\n<ol id=\"x-ck12-OWUwYWY0OWQyNmU3MDlmY2NkZjA3ODI3YWE2MDIzZWU.-d0w\">\r\n \t<li>Why does water bead up on waxy surfaces?<\/li>\r\n \t<li>Explain capillary action.<\/li>\r\n \t<li>Define cohesion.<\/li>\r\n \t<li>Define adhesion.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Review<\/h3>\r\n<ol id=\"x-ck12-MzcwOTYyY2YzZDBkMGYzZDJlOTg3ZmNhNDdhZDcwZjk.-udl\">\r\n \t<li>What is surface tension?<\/li>\r\n \t<li>What is vapor pressure?<\/li>\r\n \t<li>How does temperature affect vapor pressure?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<h2 class=\"x-ck12-data-problem-set\">Glossary<\/h2>\r\n<div class=\"x-ck12-data-vocabulary\">\r\n<ul id=\"x-ck12-NjkyNThhNGIxOGZiNWZjZDFiNzhiZTYxNjBhMzMzMTE.-6dz\">\r\n \t<li><strong> surface tension: <\/strong> The attraction between molecules at the surface of a liquid.<\/li>\r\n \t<li><strong> vapor pressure: <\/strong> The pressure of the vapor produced by evaporation of a liquid or solid above the liquid or solid in a closed container.<\/li>\r\n<\/ul>\r\n<\/div>","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Objectives<\/h3>\n<div class=\"x-ck12-data-objectives\">\n<ul id=\"x-ck12-NGQzYjBkZWMxMmUyYWJkYTJiMjVmNDczOGNkZTY2OWE.-jv6\">\n<li style=\"text-align: left;\">Define surface tension.<\/li>\n<li style=\"text-align: left;\">Define vapor pressure.<\/li>\n<li style=\"text-align: left;\">Explain the physical\u00a0properties of water in terms of hydrogen bonding.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div class=\"textbox examples\">\n<h3>What is this pan used for?<\/h3>\n<div style=\"width: 249px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212326\/20140811155539189562.jpeg\" alt=\"An evaporation pan is used to measure the rate at which water evaporates\" width=\"239\" height=\"179\" \/><\/p>\n<p class=\"wp-caption-text\">Evaporation pan. Courtesy of <a href=\"http:\/\/commons.wikimedia.org\/wiki\/File:Evaporation_pan.jpg\">NOAA<\/a>.<\/p>\n<\/div>\n<p id=\"x-ck12-MTQ2NmIzNTQ2MWJlZmRhNTEzNTE1NzNiYTQ1NjIyYjY.-jpx\">\u00a0Water loss to the atmosphere is a significant problem in many parts of the world.\u00a0 When water supplies are low, anything that can be done to decrease water loss is important for farmers.\u00a0 An evaporation pan (seen above) can be used to measure how fast water evaporates in a given location.\u00a0 This information can be used as part of projects to develop ways to cut down on evaporation and increase the amount of usable water in a region.<\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<h2>Properties of Water<\/h2>\n<p id=\"x-ck12-YzVhMjY3NmNiYzJhYzhlYTkxN2JiMWQyYWY2ZmE2YTY.-ykp\">Compared to other molecular compounds of relatively low molar mass, ice melts at a very high temperature.\u00a0 A great deal of energy is required to break apart the hydrogen-bonded network of ice and return it to the liquid state.\u00a0 Likewise, the boiling point of water is very high.\u00a0 Most molecular compounds of similar molar mass are gases at room temperature.<\/p>\n<h2>Surface Tension<\/h2>\n<p id=\"x-ck12-ZjkyMjcxNzI3YmI5OTBiNWNkZDI2MWM3M2U2NGYzNDM.-hld\">Water has a high <strong> surface <\/strong> <strong> tension <\/strong> (attraction between molecules at the surface of a liquid) because of its hydrogen bonding.\u00a0 Liquids that cannot hydrogen bond do not exhibit nearly as much surface tension.\u00a0 Surface tension can be seen by the curved meniscus that forms when water is in a thin column such as a graduated cylinder or a buret.<\/p>\n<div id=\"x-ck12-ZjA1MTIwNzk4OGU2YmNhNDZhNmE4NWY3ODRkNTNmNmE.-dwb\" class=\"x-ck12-img-thumbnail x-ck12-nofloat\">\n<div style=\"width: 138px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" id=\"x-ck12-OTgwNDUtMTM2NzI1ODE3MS0xMS02MS1zaHV0dGVyc3RvY2tfMTQ2MjIxOQ..\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212328\/20140811155539562459.jpeg\" alt=\"Water forms a meniscus because of the surface tension generated by water's hydrogen bonding\" width=\"128\" height=\"192\" longdesc=\"The%20meniscus%20of%20water%20in%20a%20graduated%20cylinder%20forms%20because%20of%20water%E2%80%99s%20hydrogen%20bonding.\" \/><\/p>\n<p class=\"wp-caption-text\">Figure 1. The meniscus of water in a graduated cylinder forms because of water\u2019s hydrogen bonding. Image by Peter Witkop, 2014. http:\/\/www.shutterstock.com.<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<h2>Vapor Pressure<\/h2>\n<p id=\"x-ck12-Y2FlODU5YTMwMTBiMTZjOWNkMGMwMTEzYTBmYjFmYWY.-qzt\">The <strong> vapor <\/strong> <strong> pressure <\/strong> of a liquid is the pressure of the vapor produced by evaporation of a liquid or solid above the liquid or solid in a closed container. The hydrogen bonding between liquid water molecules explains why water has an unusually low vapor pressure.\u00a0 Relatively few molecules of water are capable of escaping the surface of the liquid and enter the vapor phase.\u00a0 Evaporation is slow and thus the vapor exerts a low pressure in a closed container.\u00a0 Low vapor pressure is an important physical property of water, since lakes, oceans, and other large bodies of water would all tend to evaporate much more quickly otherwise.<\/p>\n<p id=\"x-ck12-M2I3N2Q4OGI4NmYyM2IzZjA4OWFiMzgwYTc0YzZkNzQ.-ynd\">Vapor pressure is influenced by temperature. As the temperature increases, more molecules are released from the surface of the liquid.\u00a0 This increases movement above the liquid surface, increasing the pressure in the vapor stage. \u00a0The image below\u00a0illustrates the effect of temperature on vapor pressure.<\/p>\n<div style=\"width: 260px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212329\/20140811155539711545.png\" alt=\"As temperature increases, vapor pressure increases as well\" width=\"250\" height=\"260\" \/><\/p>\n<p class=\"wp-caption-text\">Figure 2. From Garnix\/Wikipedia. http:\/\/commons.wikimedia.org\/wiki\/File:Dampfdruck05.png.<\/p>\n<\/div>\n<div class=\"textbox key-takeaways\">\n<h3>Summary<\/h3>\n<ul id=\"x-ck12-NWQ4NDYzYThhYzQxZTBlYzNhODg2ZmI5YmFiMTAzN2U.-6lv\">\n<li>Water has high surface tension because of extensive hydrogen bonding.<\/li>\n<li>The vapor pressure of water is low due to hydrogen bonding.<\/li>\n<li>Vapor pressure increases as temperature increases.<\/li>\n<\/ul>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Practice<\/h3>\n<p>Use the link below to answer the following questions:<\/p>\n<p id=\"x-ck12-MGQ0N2YyZjhkOTdjY2Y1OGJlY2ZmYzlhZWU2MTUyMjg.-ukv\"><a href=\"http:\/\/science.howstuffworks.com\/environmental\/earth\/geophysics\/h2o7.htm%20\"> http:\/\/science.howstuffworks.com\/environmental\/earth\/geophysics\/h2o7.htm <\/a><\/p>\n<ol id=\"x-ck12-OWUwYWY0OWQyNmU3MDlmY2NkZjA3ODI3YWE2MDIzZWU.-d0w\">\n<li>Why does water bead up on waxy surfaces?<\/li>\n<li>Explain capillary action.<\/li>\n<li>Define cohesion.<\/li>\n<li>Define adhesion.<\/li>\n<\/ol>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Review<\/h3>\n<ol id=\"x-ck12-MzcwOTYyY2YzZDBkMGYzZDJlOTg3ZmNhNDdhZDcwZjk.-udl\">\n<li>What is surface tension?<\/li>\n<li>What is vapor pressure?<\/li>\n<li>How does temperature affect vapor pressure?<\/li>\n<\/ol>\n<\/div>\n<h2 class=\"x-ck12-data-problem-set\">Glossary<\/h2>\n<div class=\"x-ck12-data-vocabulary\">\n<ul id=\"x-ck12-NjkyNThhNGIxOGZiNWZjZDFiNzhiZTYxNjBhMzMzMTE.-6dz\">\n<li><strong> surface tension: <\/strong> The attraction between molecules at the surface of a liquid.<\/li>\n<li><strong> vapor pressure: <\/strong> The pressure of the vapor produced by evaporation of a liquid or solid above the liquid or solid in a closed container.<\/li>\n<\/ul>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-2716\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Chemistry Concepts Intermediate. <strong>Authored by<\/strong>: Calbreath, Baxter, et al.. <strong>Provided by<\/strong>: CK12.org. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/www.ck12.org\/book\/CK-12-Chemistry-Concepts-Intermediate\/\">http:\/\/www.ck12.org\/book\/CK-12-Chemistry-Concepts-Intermediate\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC: Attribution-NonCommercial<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":29,"menu_order":3,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Chemistry Concepts Intermediate\",\"author\":\"Calbreath, Baxter, et al.\",\"organization\":\"CK12.org\",\"url\":\"http:\/\/www.ck12.org\/book\/CK-12-Chemistry-Concepts-Intermediate\/\",\"project\":\"\",\"license\":\"cc-by-nc\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2716","chapter","type-chapter","status-publish","hentry"],"part":2336,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2716","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/users\/29"}],"version-history":[{"count":8,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2716\/revisions"}],"predecessor-version":[{"id":3400,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2716\/revisions\/3400"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/parts\/2336"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2716\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/media?parent=2716"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapter-type?post=2716"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/contributor?post=2716"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/license?post=2716"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}