So in this example question, it says how many moles of chlorine gas are an 8.33 * 10 to the 37 molecules. All right. So to be able to do this question, we need to realize that we're trying to go from molecules to moles, right? And to be able to do that, we're going to have to utilize the conversion factor that we have up here, all right, so that those molecules are our given amount.
Remember, we're setting this up as though it is a dimensional analysis question. Although we're dealing with mole concept, it still hinges on the idea of dimensional analysis where we have our given amount and then we need to get to our end amount. And to do that we utilize conversion factors. So if you don't quite remember the steps necessary to do this, go back and take a look on our videos on dimensional analysis.
All right. So our given amount is 8.33 * 10 to the 37 molecules of CL2. And we need to get to our end amount, which will be in moles, moles of CL2. Now to be able to go from given amount to end amount, we have to utilize our conversion factor. So our conversion factor is this part up here. Now we need molecules to cancel out. So Avogadro's number in molecules have to go on the bottom.
So we're going to put molecules of CL2 here on the bottom, and that's equal to 1 mole of CL2 on the top. So here molecules will cancel out and we'll be left with moles at the end. So what you're going to do is make sure you put these in parentheses in your calculator, otherwise you may get an incorrect answer. So it's going to be 8.33 * 10 to the 37 divided by Avogadro's number.
Now if you do this correctly, what you'll get as your answer at the end will be 1.38 * 10 to the 14 moles of CL2. So that would mean that option C would be our correct answer. So again, we're setting this up as though it's a dimensional analysis question where we have our given amount, we have to know what our end amount will be and to get from the given amount to the end amount, we have to utilize a conversion factor or two.
In this particular case, it was just one conversion factor that was utilized in order to get to our final answer, OK. But keep in mind, if we're trying to go between moles and particles, meaning any one of these terms here, we're going to have to utilize Avogadro's number at some point.
