A gas with an initial temperature of 900°C undergoes the process shown in FIGURE EX18.35. a. What type of process is this?

Video transcript

Hey, everyone in this problem, a gaseous substance at 650 degrees Celsius is treated through the processes represented graphically below, identify the process. We have four multiple choice options. Option A iso choric option B isobaric option C isothermal and D none of the above. So in order to answer this problem, you'll have to be familiar with the different types of processes is so means that the process involves the volume of the gas not changing. Fortunately, for us, just by looking at the graph, we can see that's not the case because one of the graphs axes is a volume axis. If the process was iso choric and the volume would be totally the same and we would have a vertical line somewhere on the graph. But we don't see that. So we can rule out the possibility that it's iso coric. So it can't be option A isobaric refers to a process where the pressure is constant. This graph includes a pressure axis and if the pressure was constant, then we would have a horizontal line at some point on the axis and it would go through the graph. But again, just from looking at the graph, we can see that it is clearly not the case. So we can rule out option B as well. It is neither iso coric nor isobaric. Option C is isothermal, an isothermal process is one where the temperature stays the same. Now, we don't have a temperature access. So we can't determine whether or not this is the case as easily. But an important characteristic of isothermal processes is that the pressure multiplied by the volume is constant. The pressure multiplied by the volume is always going to be the same. So we can test the validity of whether or not it's isothermal by testing out different points on the graph and seeing if PV always gives us the same numerical result. So first, let's look at the point at the top of the graph where the pressure is at eight atmospheres and the volume is at four liters well, eight multiplied by four is 32. So we should expect everywhere along the graph, the pressure multiplied by the volume, they give a numerical result of two. Let's look at 0.1 on the graph where the pressure is at two atmospheres and the volume is at 16. Well, two multiplied by 16 is also 32. So that checks out, let's also look at the point where we have these orange dotted lines where the pressure is at four atmospheres and the volume is at eight liters. Once again, that's four multiplied by eight, which again, gives us a numerical value of 32. So, so from our tests, it seems like the pressure multiplied by the volume is in fact constant. So it seems safe to assume that the process is isothermal and the correct answer to the problem is option C and that is really it. I hope this video helped you out. If you're unclear on some things, please check out some of our other videos which will hopefully give you more practice with these types of problems. But that's all for now. I hope you all have a lovely night. Bye bye.