{"id":2670,"date":"2016-08-24T15:23:18","date_gmt":"2016-08-24T15:23:18","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/?post_type=chapter&#038;p=2670"},"modified":"2017-08-28T22:04:52","modified_gmt":"2017-08-28T22:04:52","slug":"exothermic-and-endothermic-processes","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/chapter\/exothermic-and-endothermic-processes\/","title":{"raw":"Exothermic and Endothermic Processes","rendered":"Exothermic and Endothermic Processes"},"content":{"raw":"<h1 id=\"x-ck12-VGhlcm1vY2hlbWlzdHJ5-chapter\">Thermochemistry<\/h1>\r\n<div class=\"x-ck12-data\"><\/div>\r\n<div class=\"textbox learning-objectives\">\r\n<h3>Learning Objectives<\/h3>\r\n<h1 id=\"x-ck12-RXhvdGhlcm1pYyBhbmQgRW5kb3RoZXJtaWMgUHJvY2Vzc2Vz\">Exothermic and Endothermic Processes<\/h1>\r\n<div class=\"x-ck12-data-objectives\">\r\n<ul id=\"x-ck12-ZWMzZTg4MjcxMDIyZjY5NDM2ZjYwNmZiNjIwZjAzOWM.-wox\">\r\n \t<li>State the law of conservation of energy.<\/li>\r\n \t<li>Define and endothermic process.<\/li>\r\n \t<li>Define an exothermic process.<\/li>\r\n \t<li>Make conversions involving heat units.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox examples\">\r\n<h3>Examples<\/h3>\r\n&nbsp;\r\n<p id=\"x-ck12-N2Q4N2NkZDNmNDdhZDg4YTY5ZjJmMjQ2NGVlNDM0NWE.-prh\"><span class=\"x-ck12-img-inline\"><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212558\/20140811155646710337.jpeg\" alt=\"Heat flows from a warm object to a cold object\" width=\"400\" \/><\/span><\/p>\r\n<p id=\"x-ck12-Mjk2NWFkMDJlMzFhMWI3NmYzMDJjNGM0MTRlNGIyZGI.-6g1\"><strong>How do you keep warm?<\/strong><\/p>\r\n<p id=\"x-ck12-Y2QxODBkZTA4ZTJjNjllOWQ3ZGY1MTQxZWUwYmNiNDk.-j5c\">A camp fire is an example of basic thermochemistry. The reaction is initiated by the application of heat from a match. The reaction converting wood to carbon dioxide and water (among other things) continues, releasing heat energy in the process. This heat energy can then be used to cook food, roast marshmallows, or just keep warm when it\u2019s cold outside.<\/p>\r\n\r\n<\/div>\r\n&nbsp;\r\n<h3>Exothermic and Endothermic Processes<\/h3>\r\n<p id=\"x-ck12-YzFhMjYzYjA1NDZjYmYyMzFlODk3YzYyNzc3NGEzZDI.-sfo\">When physical or chemical changes occur, they are generally accompanied by a transfer of energy. The <strong>law of conservation of energy <\/strong>states that in any physical or chemical process, energy is neither created nor destroyed. In other words, the entire energy in the universe is conserved. In order to better understand the energy changes taking place during a reaction, we need to define two parts of the universe, called the system and the surroundings. The <strong>system <\/strong>is the specific portion of matter in a given space that is being studied during an experiment or an observation. The\u00a0<strong>surroundings <\/strong>is everything in the universe that is not part of the system. In practical terms for a laboratory chemist, the system is the particular chemicals being reacted, while the surroundings is the immediate vicinity within the room. During most processes, energy is exchanged between the system and the surroundings. If the system loses a certain amount of energy, that same amount of energy is gained by the surroundings. If the system gains a certain amount of energy, that energy is supplied by the surroundings.<\/p>\r\n<p id=\"x-ck12-OGM5NTIzODU0ZTczOTVkYzQzNGM3Mjc0ZjY2Njg3YTQ.-lai\">In the study of thermochemical processes, things are viewed from the point of view of the system. A chemical reaction or physical change is <strong>endothermic <\/strong>if heat is absorbed by the system from the surroundings. In the course of an endothermic process, the system gains heat from the surroundings and so the temperature of the surroundings decreases. The quantity of heat for a process is represented by the letter <img id=\"x-ck12-MTM2Njk1NDE0MTUxNg..\" class=\"x-ck12-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212559\/deaa0b282c5a1d56df2ebf1d9a749ce0.png\" alt=\"q\" width=\"9\" height=\"12\" \/> . The sign of\u00a0 <img class=\"x-ck12-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212559\/deaa0b282c5a1d56df2ebf1d9a749ce0.png\" alt=\"q\" width=\"9\" height=\"12\" \/> for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is <strong>exothermic <\/strong>if heat is released by the system into the surroundings. Because the surroundings is gaining heat from the system, the temperature of the surroundings increases. The sign of\u00a0 <img class=\"x-ck12-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212559\/deaa0b282c5a1d56df2ebf1d9a749ce0.png\" alt=\"q\" width=\"9\" height=\"12\" \/> for an exothermic process is negative because the system is losing heat.<\/p>\r\n\r\n<div id=\"x-ck12-OTk1ODA4MjhmMmY2MjQ3YWNhMmE2MTc5YWUyY2JiZWM.-ivm\" class=\"x-ck12-img-postcard x-ck12-nofloat\">\r\n<p id=\"x-ck12-yuz\"><img id=\"x-ck12-OTgwNDUtMTM2NTQ4NzUxNy00My00My01LjEuMy4y\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212600\/20140811155647047309.png\" alt=\"Endothermic reactions absorb heat, while exothermic reactions release heat\" longdesc=\"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-admin\/%28A%29%20Endothermic%20reaction.%20%28B%29%20Exothermic%20reaction.\" \/><\/p>\r\n<strong>Figure 17.4<\/strong>\r\n<p id=\"x-ck12-M2Y2YzdlNWI3NzdiODIyYzYzNTM0YTg0NjMwMzJhN2Q.-tfa\">(A) Endothermic reaction. (B) Exothermic reaction.<\/p>\r\n\r\n<\/div>\r\n<h4>Units of Heat<\/h4>\r\n<p id=\"x-ck12-MmM2ZGJhYmQwYzhiOWUzMzE2ZmQ2OThlZDQ1MzFlNGE.-uht\">Heat flow is measured in one of two common units: the calorie and the joule. The joule (J) is the SI unit of energy.\u00a0 The calorie is familiar because it is commonly used when referring to the amount of energy contained within food. A <strong>calorie (cal) <\/strong>is the quantity of heat required to raise the temperature of 1 gram of water by 1\u00b0C. For example, raising the temperature of 100 g of water from 20\u00b0C to 22\u00b0C would require 100\u00a0\u00d7 2 = 200 cal.<\/p>\r\n<p id=\"x-ck12-Zjg3YzFmMWJlM2UzMzMyMDQzYjBiNTE1Yjc5NGE0Mzc.-cby\">Calories contained within food are actually kilocalories (kcal). In other words, if a certain snack contains 85 food calories, it actually contains 85 kcal or 85,000 cal. In order to make the distinction, the dietary calorie is written with a capital C.<\/p>\r\n<p id=\"x-ck12-sbc\"><img id=\"x-ck12-MTM2Njk1NDE0MTUxOA..\" class=\"x-ck12-block-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212601\/d17e91d47f7eb10e40b61c101b3b4f51.png\" alt=\"1 text{kilocalorie}=1 text{Calorie} = 1000 text{calories}\" width=\"312\" height=\"14\" \/><\/p>\r\n<p id=\"x-ck12-ZTU5MGQ5Y2IyYTQ1NThlOWIyMjY4YzM0YTFjYTEyZDg.-jp1\">To say that the snack \u201ccontains\u201d 85 Calories means that 85 kcal of energy are released when that snack is processed by your body.<\/p>\r\n<p id=\"x-ck12-MjRkMzk3ZmI5NDgxMzFkYmU0M2UwMzM2ZTVlZThjZjU.-h2c\">Heat changes in chemical reactions are typically measured in joules rather than calories. The conversion between a joule and a calorie is shown below.<\/p>\r\n<p id=\"x-ck12-g5n\"><img class=\"x-ck12-block-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212602\/c0b7c0e8a744040ce4d084d0a3e856ef.png\" alt=\"1 text{ J} = 0.2390 text{ cal or 1 cal} = 4.184 text{ J}\" width=\"269\" height=\"14\" \/><\/p>\r\n<p id=\"x-ck12-OTU3MmQyOTA1ZGQzYmY4YzY2MGUxNTBjMzk2OGIzMzE.-j5y\">We can calculate the amount of heat released in kilojoules when a 400. Calorie hamburger is digested.<\/p>\r\n<p id=\"x-ck12-bgw\"><img class=\"x-ck12-block-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212603\/d806c34c5c63b69950afd63dff215401.png\" alt=\"400 cdot text{Cal} = 400 cdot text{kcal} times frac{4.184 text{ kJ}}{1 text{ kcal}}=1.67 times 10^3 text{ kJ}\" width=\"380\" height=\"39\" \/><\/p>\r\n\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Key Takeaways<\/h3>\r\n<h4>Summary<\/h4>\r\n<ul id=\"x-ck12-ZGY1Yzc4NTUyYTQwZGY0ODk2NWI1NTZiZDE3ZWIyMzU.-2n4\">\r\n \t<li>Processes of heat exchange between the system and surroundings are described.<\/li>\r\n<\/ul>\r\n<\/div>\r\n&nbsp;\r\n<div class=\"textbox exercises\">\r\n<h3>Exercises<\/h3>\r\n<h4>Practice<\/h4>\r\n<p id=\"x-ck12-MGQ5MTk4NWMxZTNiNTgwM2JhM2YxOWJmMmViNzVhMDk.-0qc\">Do the problems (as many as you have time for) at the link below:<\/p>\r\n<p id=\"x-ck12-NmJkNzAwZmQ2MzUyMmQ3ZjFhNDVhMmRiYmNjNDAyODk.-bzw\"><a href=\"http:\/\/www.chemteam.info\/Thermochem\/Thermochem-WS2.html\">http:\/\/www.chemteam.info\/Thermochem\/Thermochem-WS2.html<\/a><\/p>\r\n\r\n<h4>Review<\/h4>\r\n<p id=\"x-ck12-NmNlM2JkYzM5ZTU0NDcyNTAzOGUwZTg3Yjc3MWRiMWU.-5kf\" dir=\"ltr\"><em>Questions<\/em><\/p>\r\n\r\n<ol id=\"x-ck12-NzMzYWM1ZDQwMTNhNmFjMmQyNjNkODkwZTY1YmMwMjY.-90a\">\r\n \t<li>What does the law of conservation of energy say?<\/li>\r\n \t<li>What is a reaction called that gives off heat?<\/li>\r\n \t<li>A cake is made by mixing ingredients and placing the material in an oven for baking. What type of reaction is involved?<\/li>\r\n<\/ol>\r\n<div class=\"x-ck12-data-problem-set\"><\/div>\r\n<div class=\"x-ck12-data-vocabulary\"><\/div>\r\n<\/div>\r\n&nbsp;\r\n<div class=\"textbox learning-objectives\">\r\n<h3>Learning Objectives<\/h3>\r\n<ul>\r\n \t<li><strong>calorie (cal): <\/strong>The quantity of heat required to raise the temperature of 1 gram of water by 1\u00b0C.<\/li>\r\n \t<li><strong>endothermic: <\/strong>Heat is absorbed by the system from the surroundings.<\/li>\r\n \t<li><strong>exothermic: <\/strong>Heat is released by the system into the surroundings.<\/li>\r\n \t<li><strong>law of conservation of energy: <\/strong>In any physical or chemical process, energy is neither created nor destroyed.<\/li>\r\n \t<li><strong>surroundings: <\/strong>Everything in the universe that is not part of the system.<\/li>\r\n \t<li><strong>system: <\/strong>The specific portion of matter in a given space that is being studied during an experiment or an observation.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<h1 id=\"x-ck12-SGVhdCBDYXBhY2l0eSBhbmQgU3BlY2lmaWMgSGVhdA..\"><\/h1>\r\n[reveal-answer q=\"836080\"]Show References[\/reveal-answer]\r\n[hidden-answer a=\"836080\"]\r\n<h2>References<\/h2>\r\n<ol>\r\n \t<li>Eric Dufresne. <a href=\"http:\/\/commons.wikimedia.org\/wiki\/File:Camp_fire.jpg\">http:\/\/commons.wikimedia.org\/wiki\/File:Camp_fire.jpg <\/a>.<\/li>\r\n \t<li>CK-12 Foundation - Christopher Auyeung.<\/li>\r\n<\/ol>\r\n[\/hidden-answer]","rendered":"<h1 id=\"x-ck12-VGhlcm1vY2hlbWlzdHJ5-chapter\">Thermochemistry<\/h1>\n<div class=\"x-ck12-data\"><\/div>\n<div class=\"textbox learning-objectives\">\n<h3>Learning Objectives<\/h3>\n<h1 id=\"x-ck12-RXhvdGhlcm1pYyBhbmQgRW5kb3RoZXJtaWMgUHJvY2Vzc2Vz\">Exothermic and Endothermic Processes<\/h1>\n<div class=\"x-ck12-data-objectives\">\n<ul id=\"x-ck12-ZWMzZTg4MjcxMDIyZjY5NDM2ZjYwNmZiNjIwZjAzOWM.-wox\">\n<li>State the law of conservation of energy.<\/li>\n<li>Define and endothermic process.<\/li>\n<li>Define an exothermic process.<\/li>\n<li>Make conversions involving heat units.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div class=\"textbox examples\">\n<h3>Examples<\/h3>\n<p>&nbsp;<\/p>\n<p id=\"x-ck12-N2Q4N2NkZDNmNDdhZDg4YTY5ZjJmMjQ2NGVlNDM0NWE.-prh\"><span class=\"x-ck12-img-inline\"><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212558\/20140811155646710337.jpeg\" alt=\"Heat flows from a warm object to a cold object\" width=\"400\" \/><\/span><\/p>\n<p id=\"x-ck12-Mjk2NWFkMDJlMzFhMWI3NmYzMDJjNGM0MTRlNGIyZGI.-6g1\"><strong>How do you keep warm?<\/strong><\/p>\n<p id=\"x-ck12-Y2QxODBkZTA4ZTJjNjllOWQ3ZGY1MTQxZWUwYmNiNDk.-j5c\">A camp fire is an example of basic thermochemistry. The reaction is initiated by the application of heat from a match. The reaction converting wood to carbon dioxide and water (among other things) continues, releasing heat energy in the process. This heat energy can then be used to cook food, roast marshmallows, or just keep warm when it\u2019s cold outside.<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<h3>Exothermic and Endothermic Processes<\/h3>\n<p id=\"x-ck12-YzFhMjYzYjA1NDZjYmYyMzFlODk3YzYyNzc3NGEzZDI.-sfo\">When physical or chemical changes occur, they are generally accompanied by a transfer of energy. The <strong>law of conservation of energy <\/strong>states that in any physical or chemical process, energy is neither created nor destroyed. In other words, the entire energy in the universe is conserved. In order to better understand the energy changes taking place during a reaction, we need to define two parts of the universe, called the system and the surroundings. The <strong>system <\/strong>is the specific portion of matter in a given space that is being studied during an experiment or an observation. The\u00a0<strong>surroundings <\/strong>is everything in the universe that is not part of the system. In practical terms for a laboratory chemist, the system is the particular chemicals being reacted, while the surroundings is the immediate vicinity within the room. During most processes, energy is exchanged between the system and the surroundings. If the system loses a certain amount of energy, that same amount of energy is gained by the surroundings. If the system gains a certain amount of energy, that energy is supplied by the surroundings.<\/p>\n<p id=\"x-ck12-OGM5NTIzODU0ZTczOTVkYzQzNGM3Mjc0ZjY2Njg3YTQ.-lai\">In the study of thermochemical processes, things are viewed from the point of view of the system. A chemical reaction or physical change is <strong>endothermic <\/strong>if heat is absorbed by the system from the surroundings. In the course of an endothermic process, the system gains heat from the surroundings and so the temperature of the surroundings decreases. The quantity of heat for a process is represented by the letter <img loading=\"lazy\" decoding=\"async\" id=\"x-ck12-MTM2Njk1NDE0MTUxNg..\" class=\"x-ck12-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212559\/deaa0b282c5a1d56df2ebf1d9a749ce0.png\" alt=\"q\" width=\"9\" height=\"12\" \/> . The sign of\u00a0 <img loading=\"lazy\" decoding=\"async\" class=\"x-ck12-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212559\/deaa0b282c5a1d56df2ebf1d9a749ce0.png\" alt=\"q\" width=\"9\" height=\"12\" \/> for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is <strong>exothermic <\/strong>if heat is released by the system into the surroundings. Because the surroundings is gaining heat from the system, the temperature of the surroundings increases. The sign of\u00a0 <img loading=\"lazy\" decoding=\"async\" class=\"x-ck12-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212559\/deaa0b282c5a1d56df2ebf1d9a749ce0.png\" alt=\"q\" width=\"9\" height=\"12\" \/> for an exothermic process is negative because the system is losing heat.<\/p>\n<div id=\"x-ck12-OTk1ODA4MjhmMmY2MjQ3YWNhMmE2MTc5YWUyY2JiZWM.-ivm\" class=\"x-ck12-img-postcard x-ck12-nofloat\">\n<p id=\"x-ck12-yuz\"><img decoding=\"async\" id=\"x-ck12-OTgwNDUtMTM2NTQ4NzUxNy00My00My01LjEuMy4y\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212600\/20140811155647047309.png\" alt=\"Endothermic reactions absorb heat, while exothermic reactions release heat\" longdesc=\"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-admin\/%28A%29%20Endothermic%20reaction.%20%28B%29%20Exothermic%20reaction.\" \/><\/p>\n<p><strong>Figure 17.4<\/strong><\/p>\n<p id=\"x-ck12-M2Y2YzdlNWI3NzdiODIyYzYzNTM0YTg0NjMwMzJhN2Q.-tfa\">(A) Endothermic reaction. (B) Exothermic reaction.<\/p>\n<\/div>\n<h4>Units of Heat<\/h4>\n<p id=\"x-ck12-MmM2ZGJhYmQwYzhiOWUzMzE2ZmQ2OThlZDQ1MzFlNGE.-uht\">Heat flow is measured in one of two common units: the calorie and the joule. The joule (J) is the SI unit of energy.\u00a0 The calorie is familiar because it is commonly used when referring to the amount of energy contained within food. A <strong>calorie (cal) <\/strong>is the quantity of heat required to raise the temperature of 1 gram of water by 1\u00b0C. For example, raising the temperature of 100 g of water from 20\u00b0C to 22\u00b0C would require 100\u00a0\u00d7 2 = 200 cal.<\/p>\n<p id=\"x-ck12-Zjg3YzFmMWJlM2UzMzMyMDQzYjBiNTE1Yjc5NGE0Mzc.-cby\">Calories contained within food are actually kilocalories (kcal). In other words, if a certain snack contains 85 food calories, it actually contains 85 kcal or 85,000 cal. In order to make the distinction, the dietary calorie is written with a capital C.<\/p>\n<p id=\"x-ck12-sbc\"><img loading=\"lazy\" decoding=\"async\" id=\"x-ck12-MTM2Njk1NDE0MTUxOA..\" class=\"x-ck12-block-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212601\/d17e91d47f7eb10e40b61c101b3b4f51.png\" alt=\"1 text{kilocalorie}=1 text{Calorie} = 1000 text{calories}\" width=\"312\" height=\"14\" \/><\/p>\n<p id=\"x-ck12-ZTU5MGQ5Y2IyYTQ1NThlOWIyMjY4YzM0YTFjYTEyZDg.-jp1\">To say that the snack \u201ccontains\u201d 85 Calories means that 85 kcal of energy are released when that snack is processed by your body.<\/p>\n<p id=\"x-ck12-MjRkMzk3ZmI5NDgxMzFkYmU0M2UwMzM2ZTVlZThjZjU.-h2c\">Heat changes in chemical reactions are typically measured in joules rather than calories. The conversion between a joule and a calorie is shown below.<\/p>\n<p id=\"x-ck12-g5n\"><img loading=\"lazy\" decoding=\"async\" class=\"x-ck12-block-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212602\/c0b7c0e8a744040ce4d084d0a3e856ef.png\" alt=\"1 text{ J} = 0.2390 text{ cal or 1 cal} = 4.184 text{ J}\" width=\"269\" height=\"14\" \/><\/p>\n<p id=\"x-ck12-OTU3MmQyOTA1ZGQzYmY4YzY2MGUxNTBjMzk2OGIzMzE.-j5y\">We can calculate the amount of heat released in kilojoules when a 400. Calorie hamburger is digested.<\/p>\n<p id=\"x-ck12-bgw\"><img loading=\"lazy\" decoding=\"async\" class=\"x-ck12-block-math\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212603\/d806c34c5c63b69950afd63dff215401.png\" alt=\"400 cdot text{Cal} = 400 cdot text{kcal} times frac{4.184 text{ kJ}}{1 text{ kcal}}=1.67 times 10^3 text{ kJ}\" width=\"380\" height=\"39\" \/><\/p>\n<div class=\"textbox key-takeaways\">\n<h3>Key Takeaways<\/h3>\n<h4>Summary<\/h4>\n<ul id=\"x-ck12-ZGY1Yzc4NTUyYTQwZGY0ODk2NWI1NTZiZDE3ZWIyMzU.-2n4\">\n<li>Processes of heat exchange between the system and surroundings are described.<\/li>\n<\/ul>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"textbox exercises\">\n<h3>Exercises<\/h3>\n<h4>Practice<\/h4>\n<p id=\"x-ck12-MGQ5MTk4NWMxZTNiNTgwM2JhM2YxOWJmMmViNzVhMDk.-0qc\">Do the problems (as many as you have time for) at the link below:<\/p>\n<p id=\"x-ck12-NmJkNzAwZmQ2MzUyMmQ3ZjFhNDVhMmRiYmNjNDAyODk.-bzw\"><a href=\"http:\/\/www.chemteam.info\/Thermochem\/Thermochem-WS2.html\">http:\/\/www.chemteam.info\/Thermochem\/Thermochem-WS2.html<\/a><\/p>\n<h4>Review<\/h4>\n<p id=\"x-ck12-NmNlM2JkYzM5ZTU0NDcyNTAzOGUwZTg3Yjc3MWRiMWU.-5kf\" dir=\"ltr\"><em>Questions<\/em><\/p>\n<ol id=\"x-ck12-NzMzYWM1ZDQwMTNhNmFjMmQyNjNkODkwZTY1YmMwMjY.-90a\">\n<li>What does the law of conservation of energy say?<\/li>\n<li>What is a reaction called that gives off heat?<\/li>\n<li>A cake is made by mixing ingredients and placing the material in an oven for baking. What type of reaction is involved?<\/li>\n<\/ol>\n<div class=\"x-ck12-data-problem-set\"><\/div>\n<div class=\"x-ck12-data-vocabulary\"><\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"textbox learning-objectives\">\n<h3>Learning Objectives<\/h3>\n<ul>\n<li><strong>calorie (cal): <\/strong>The quantity of heat required to raise the temperature of 1 gram of water by 1\u00b0C.<\/li>\n<li><strong>endothermic: <\/strong>Heat is absorbed by the system from the surroundings.<\/li>\n<li><strong>exothermic: <\/strong>Heat is released by the system into the surroundings.<\/li>\n<li><strong>law of conservation of energy: <\/strong>In any physical or chemical process, energy is neither created nor destroyed.<\/li>\n<li><strong>surroundings: <\/strong>Everything in the universe that is not part of the system.<\/li>\n<li><strong>system: <\/strong>The specific portion of matter in a given space that is being studied during an experiment or an observation.<\/li>\n<\/ul>\n<\/div>\n<h1 id=\"x-ck12-SGVhdCBDYXBhY2l0eSBhbmQgU3BlY2lmaWMgSGVhdA..\"><\/h1>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q836080\">Show References<\/span><\/p>\n<div id=\"q836080\" class=\"hidden-answer\" style=\"display: none\">\n<h2>References<\/h2>\n<ol>\n<li>Eric Dufresne. <a href=\"http:\/\/commons.wikimedia.org\/wiki\/File:Camp_fire.jpg\">http:\/\/commons.wikimedia.org\/wiki\/File:Camp_fire.jpg <\/a>.<\/li>\n<li>CK-12 Foundation &#8211; Christopher Auyeung.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n","protected":false},"author":1507,"menu_order":4,"template":"","meta":{"_candela_citation":"[]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2670","chapter","type-chapter","status-publish","hentry"],"part":2338,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2670","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\/1507"}],"version-history":[{"count":6,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2670\/revisions"}],"predecessor-version":[{"id":3619,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2670\/revisions\/3619"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/parts\/2338"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2670\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/media?parent=2670"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapter-type?post=2670"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/contributor?post=2670"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/license?post=2670"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}