[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-656946-105":59,"doc-detail-656946-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","pv-diagrams-isobaric-isochoric-isothermal-and-adiabatic-processes","PV Diagrams - Isobaric, Isochoric, Isothermal, and Adiabatic Processes","","PV diagrams describe how gas pressure changes as volume changes, using four key process types: isobaric, isochoric, isothermal, and adiabatic. The material explains each process in terms of constraints on pressure, volume, temperature, and heat flow, and connects those constraints to work and the first law of thermodynamics. For isobaric heating, pressure stays constant while expansion increases volume, so the gas does work with W = -PΔV and the area under the PV curve represents work. For isochoric heating, volume remains fixed so work is zero and added heat raises internal energy, with pressure rising alongside temperature through the ideal gas law.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":30,"@type":76,"position":81},"https://docshare.wps.com/document/technology/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/pv-diagrams-isobaric-isochoric-isothermal-and-adiabatic-processes/656946/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/pv-diagrams-isobaric-isochoric-isothermal-and-adiabatic-processes/656946.png","ImageObject",300,407,{"name":92,"@type":93},"Guten Appetit_Joghurt","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-02","2026-10-25",true,{"@type":102,"interactionType":103,"userInteractionCount":29},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What is a PV diagram and what axes does it use?","Question",{"text":112,"@type":113},"A PV diagram graphs pressure as a function of volume. Pressure is shown in pascals (Pa) and volume in cubic metres (m³).","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"In an isobaric process, what stays constant and how is work determined?",{"text":117,"@type":113},"In an isobaric process the gas pressure stays constant while the gas expands. The work done relates to W = -PΔV, and the area under the PV line represents the work done.",{"name":119,"@type":110,"acceptedAnswer":120},"Why is no work done in an isochoric process?",{"text":121,"@type":113},"In an isochoric process the volume remains constant, so the displacement is zero. Since W = Fd and d = 0, work is 0 J and heat added increases internal energy (ΔU = Q).","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},656946,1793090883,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":29,"category_name":30,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":29,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":34,"language":139,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":140,"faqs":141,"seo_title":142,"seo_description":67,"update_tm":143,"read_time":144},1374408768420,"https://ap-avatar.wpscdn.com/davatar_6f874abed73319feea01a86fa6f0fab8","From the last section, you were probably wondering what happens when we do something like add heat to a sealed cylinder.  \n• This sounds like a pretty dangerous idea if you think back to the WHMIS training you had about compressed gas cylinders in Science 10. You might be thinking that it could make the cylinder explode because of an increase in pressure.  \n• These are the sorts of situations we can consider when we Pressure is measured in either Pascals (Pa) look at PV diagrams. or Newtons per metre squared (N/m2) .  \n◦ A PV diagram is a graph of Pressure as a function of Volume is measured in metres cubed (m3) . Volume.  \nThere are four different situations that you can expect to see shown in PV diagrams:  \n1. Isobaric: the gas is held at a constant pressure  \n2. Isochoric: the gas is held at a constant volume  \n3. Isothermal: the gas is held at a constant temperature  \n4. Adiabatic: No heat flows in or out of the gas  \nIsobaric Processes and Work  \n[https://www.youtube.com/watch?v=Xcrco59p40o](https://www.youtube.com/watch?v=Xcrco59p40o)  \nIsothermal, Isometric, & Adiabatic Processes  \n[https://www.youtube.com/watch?v=nkOtOMNS5bQ](https://www.youtube.com/watch?v=nkOtOMNS5bQ)  \nIsobaric = Constant Pressure  \nIsobaric is actually a pretty easy thing to show on a PV diagram, and also pretty easy to understand from an example of a situation in which it is happening.  \n• Imagine that you have a cylinder filled with a gas. Atthe top is a movable piston that has a few kilograms mass.  \n◦ At the start the pressure is a certain amount for the volume of gas involved.  \n• We place a heat source under the cylinder and slowly heat it up.  \n◦ Since this is an isobaric process, the pressure must stay the same as it was at the start.  \n◦ We also expect that with the extra internal energy  \nIllustration 1: A cylinder of gas is heated so that it expands while keeping its pressure constant.  \nthe molecules have gained from the heat source, they will be bouncing around a bit more.  \n▪ This must result in the gas expanding in the cylinder!  \n• The gas will do work against the piston as it expands, where W = Fd.  \n◦ The force is caused by the pressure acting on the surface area of the piston, so we can use the formula    \nF = PA  \nF = force (N) P = pressure (Pa = N/m2) A = area of the piston (m2)  \n◦ We can substitute the two formulas together to  \nget...  \nW = Fd F = PA  \nW = PAd  \nW = -PΔV  \n• This formula would let us calculate the work done by the gas on the piston as it expands.  \nRemember from math that volume can be calculated for a cylinder by taking the area of its end and multiplying it by the height. The distance the piston moved up in this example is like a change in height. This means that ΔV = Ad.  \nThe negative sign is added in the final formula on the AP data sheet so we get the correct sign for W.  \nExample 1: A gas at 4.0e5 Pa is in a cylinder with a piston. During an isobaric process the gas is heated and expands from 0.25 m3 to 0.55 m3. Determine the work done by the gas on the cylinder, and sketch a PV diagram of the situation.  \nW = -PΔV  \nW = -P (Vf– Vi)  \nW = -4.0e5 (0.55 – 0.25)  \nW = -1.2e5 J  \nThe PV diagram shows a gas going from a smaller to a bigger volume, while the pressure stays constant.  \n• Since the volume of the gas increased, we know work was done by the gas.  \n• The arrow has been added to show the way the process went from start to finish.  \n• If you look at how we calculated the work done, you might notice that it would have been the same answer if we had calculated the area under the graph. The  \nP (N/m2)  \nIllustration 2: An isobaric process where the gas does work.  \narea under the line on a PV diagram is the work done!  \n◦ This is true for any PV diagram, so keep it in mind.  \nV (m3)  \nWe can also realize something about the temperature change that must be happening if we use the ideal gas law.  \n• Since the pressure (P), the amount of gas (n), and the gas constant (R) all stay constant...  \nPV = nRT ","cbCaim1UBRM09u45","https://ap.wps.com/l/cbCaim1UBRM09u45","pdf",303033,"English","# PV diagrams overview\n## Four process types in PV diagrams\n## Isobaric process and work\n## Isochoric process and first law of thermodynamics\n## Temperature links via the ideal gas law","[{\"question\":\"What is a PV diagram and what axes does it use?\",\"answer\":\"A PV diagram graphs pressure as a function of volume. Pressure is shown in pascals (Pa) and volume in cubic metres (m³).\"},{\"question\":\"In an isobaric process, what stays constant and how is work determined?\",\"answer\":\"In an isobaric process the gas pressure stays constant while the gas expands. The work done relates to W = -PΔV, and the area under the PV line represents the work done.\"},{\"question\":\"Why is no work done in an isochoric process?\",\"answer\":\"In an isochoric process the volume remains constant, so the displacement is zero. Since W = Fd and d = 0, work is 0 J and heat added increases internal energy (ΔU = Q).\"}]","PV Diagrams - Isobaric, Isochoric, Isothermal, and Adiabatic Processes | PDF",1792971729,18]