Standard Temperature and Pressure Example 2

Jules Bruno
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here. The example. Question says how many moles of chlorine gas occupy a volume of 15.7 leaders at STP? Alright, so here they're talking about determining the moles of an ideal gas. They're giving us the volume off that gas at STP here. We can use the conversion factor that we know exists with standard molar volume. We're going to say we have 15.7 leaders and we're gonna say here that the conversion factor is for every one mole of any gas at STP, the volume is 24 22 4 leaders here leaders cancel out and I'll have my moles, which comes out 2.701 moles off C l two. So this is one way that we get our answer. What else we could do is we could have also said that we have 15.7 leaders, which is our volume. And then we have STP, which is pressure and temperature. We could have said that are moles equals P V over r T and we would have gotten the same exact answer because here this would have been one atmosphere this year is 15 7 leaders. Then here we have our our constant with its units. Don't forget the units. Times temperature at STP is to 73.15 kelvin, and if we worked it out, we get the same exact moles for l two. So just realize that there's two ways that we can approach a question like this, using it with the conversion factor of one mole for every 22.4 leaders, or by using it through traditional means with the ideal gas law.