From the given molar mass and empirical formula of several
compo...

Question

From the given molar mass and empirical formula of several 
compounds, find the molecular formula of each compound. 
a. C4H9, 114.22 g/mol

Accepted Answer

Hey folks, welcome back. So we have a compound that has a molar mass of 84.14 g per mole. So that is going to be the molecular formula Mueller mass. Okay, identify the molecular formula of the compound given the empirical formula Ch two. So we do have the empirical formula. Once we have that and the molar mass of the molecular formula, we can identify the molecular formula very easily. So what we're gonna do is take see each to and find its molar mass because we want to see how many of these empirical formulas are going to fit into the molar mass of the molecular formula. Okay, so carbon, we have only one carbon. Right? And that's gonna weigh 12.1 g per mole. So those molar masses are all going to be found on the periodic table for the hydrogen is we have two of them And they weigh 1.1 each. So that will give us 2. g. And then when we add that together we get 14. And that is g per mole. So that is the molar mass of the empirical formula. But we have molar mass of the molecular formula. So what we're going to do now is actually take the molar mass of the molecular formula and divided by the empirical formula mass. Okay, so we have 84 0. grams per mole, divided by 14 0. grams per mole. Notice that the grams and moles cancel out. And now we're just going to get a ratio. Okay, and that's going to give us 5.997. We're going to round it up to six. Okay, So basically that means is that we have six of CH two within the molecular formula. So to find the molecular formula, We're gonna take the empirical Formula Ch two And we're going to multiply it by that number, by that ratio that we found. So that's going to give us C6 H 12. Okay, so that is actually our molecular formula C6 H 12. Right. Thanks so much for watching. We'll see you in the next video.

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