{"id":878,"date":"2021-06-07T00:07:50","date_gmt":"2021-06-07T04:07:50","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/thermo1\/chapter\/what-is-a-pure-substance\/"},"modified":"2022-08-02T19:37:52","modified_gmt":"2022-08-02T23:37:52","slug":"what-is-a-pure-substance","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/thermo1\/chapter\/what-is-a-pure-substance\/","title":{"raw":"2.1 Pure substance","rendered":"2.1 Pure substance"},"content":{"raw":"<div class=\"what-is-a-pure-substance?\">\r\n\r\nA [pb_glossary id=\"493\"]pure substance[\/pb_glossary] refers to a matter that has a homogeneous and definite chemical composition. A pure substance may exist in a single phase, such as liquid water, ice, and CO<sub>2<\/sub><sub>\u00a0<\/sub>gas. It can also exist as a multi-phase mixture, such as a mixture of liquid water and water vapour in equilibrium.\r\n\r\n&nbsp;\r\n\r\nAir is a common working fluid used in many thermal devices. Can air be treated as a pure substance? Although air is a mixture consisting of roughly 78% of nitrogen, 21% of oxygen, and trace amounts of other gases and moisture, air is homogeneous and has distinct properties without phase changes in its composition in many thermodynamic processes. In such conditions, we can treat air as a pure substance.\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Practice Problems<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<p class=\"import-Normal\" style=\"text-align: justify\">[h5p id=\"54\"]<strong>\r\n<\/strong><\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>","rendered":"<div class=\"what-is-a-pure-substance?\">\n<p>A <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_878_493\">pure substance<\/a> refers to a matter that has a homogeneous and definite chemical composition. A pure substance may exist in a single phase, such as liquid water, ice, and CO<sub>2<\/sub><sub>\u00a0<\/sub>gas. It can also exist as a multi-phase mixture, such as a mixture of liquid water and water vapour in equilibrium.<\/p>\n<p>&nbsp;<\/p>\n<p>Air is a common working fluid used in many thermal devices. Can air be treated as a pure substance? Although air is a mixture consisting of roughly 78% of nitrogen, 21% of oxygen, and trace amounts of other gases and moisture, air is homogeneous and has distinct properties without phase changes in its composition in many thermodynamic processes. In such conditions, we can treat air as a pure substance.<\/p>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Practice Problems<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p class=\"import-Normal\" style=\"text-align: justify\">\n<div id=\"h5p-54\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-54\" class=\"h5p-iframe\" data-content-id=\"54\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"S_2.1_Q\"><\/iframe><\/div>\n<\/div>\n<p><strong><br \/>\n<\/strong><\/p>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_878_493\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_878_493\"><div tabindex=\"-1\"><p>A pure substance refers to a matter that has a homogeneous and definite chemical composition. A pure substance may exist in a single phase or as a multi-phase mixture.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":175,"menu_order":2,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[47],"contributor":[],"license":[],"class_list":["post-878","chapter","type-chapter","status-publish","hentry","chapter-type-standard"],"part":246,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/pressbooks\/v2\/chapters\/878","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/wp\/v2\/users\/175"}],"version-history":[{"count":17,"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/pressbooks\/v2\/chapters\/878\/revisions"}],"predecessor-version":[{"id":3961,"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/pressbooks\/v2\/chapters\/878\/revisions\/3961"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/pressbooks\/v2\/parts\/246"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/pressbooks\/v2\/chapters\/878\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/wp\/v2\/media?parent=878"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/pressbooks\/v2\/chapter-type?post=878"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/wp\/v2\/contributor?post=878"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/thermo1\/wp-json\/wp\/v2\/license?post=878"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}