Composition

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##### Top Chemistry 101 Educators ##### Stephanie C.

University of Central Florida  ##### Allea C.

University of Maryland - University College

### Video Transcript

So here we have this molecule carbon tantra quarry, and we know they've given to us The molar mass is 153.8 grams per mole. Really? Are men trying to find the mass? You're trying to find the mass of one molecule so mass per molecule. She's basically mass over Molik. It's all right. So let's just date the, um, formulas that we know. We know that to calculate number of molecules, we just take malls and multiply it by. I'm a guard just number, and then we would need more. So to find walls we just take mass and divided by molar mass, Right? Okay, So, basically to self for the mass of one molecule, we're gonna take this mass and divided by this number of molecules. Just put a docked here, this mass. And why, by this number of molecules No, we were only given, uh, molar s here. We don't know a mass, but to make things so basically we can make up any of us. We want in this question, cause it because it would give us the same number because the mass per molecule off any month of a compound can't really change. It can't change per save. No matter like which mass you use. The massive one molecule would always be constant, so we can use any much we want. So let's use thumbs. The same figure here, 1.153 point eight grams from all and 153.8 Gramps, which would give us one more and would give us number of molecules equivalent to have a god chose constant. So let's work this out sweats for showing more my most. So we said that we would use the exact same figure as the more mass 153.8 grams. You could have used any mask you wants and you would get the same number. I hope you believe me by that. But you really can, because that mass would change the moles and it would just change the most enough to give you the exact same number of modules womb. Okay, so this without even using calculator, equals to one more. So now eight. Writing out this word number of molecules, just don't call it ma'lik. Molecules is equivalent to one wall times. Have a god just number. And she's there for equal to just a religious number, cam, because that's what normal is. Uh huh. So Mama can write out that whole remember, but yes, it's No. We're just gonna divide mass over the molecules this year. 100 and 53.8 grams over and a Can you write it out this time? Six point. Oh, too true Zero. Since rounded out times tend to the 23 right? So and no units, cause it's a number of molecules. If we just do this quick vision, we get 2.5539 and tested out. Use another number from us and you'll see that you'll still end up with 2.539 His mass per molecule. It can't change with mass. Poor number molecules. Yeah, it's independent. So illegals, 2.5539 times 10 to the exponents. Negative. 22. So, yeah, there we have it. McMaster University

#### Topics

Composition

##### Top Chemistry 101 Educators ##### Stephanie C.

University of Central Florida  ##### Allea C.

University of Maryland - University College