This is the answer to Chapter 19. Problem number seven Fromthe Smith Organic chemistry. Textbook on this problem says, Explain how you could use I r spectroscopy to distinguish among the following three compounds. So we're talking about the three molecules that have drawn here. Um, and we're talking about how to use I r to distinguish between the three of these. Um and so basically, what we need to do is look for the signals that are going to be different for each molecule here. So they're all gonna have sp three hybridized carbon bound to hydrogen. So they're all gonna have i our signals around 28 52 to 3000 wave number. So we can safely ignore those signals. They're not gonna help us here. However, for this first molecule, um, our function are functionality here. Eyes Oops. Wanted that in green. So our functionality here is a car box, Silly Gassid, and, um, in the i r of a carb oxalic acid. We're going to have a peek around 17. 10 wave number. Um, and that's gonna be our carbon oxygen double bond. Ah, and then we're gonna have a second peak. Um, it probably Ah, wide broad peak somewhere between 2500 and 30. 500 wave number. Um, And that is gonna be due to the O h of a carb oxalic acid. So remember, that's ah, it's a little different than the O. H oven alcohol, but it's sort of around the same region. And so if we have this carb oxalic acid, we should see both of those signals. Um, so the middle molecule here is an esther. Um, And since it's an Esther, the, uh, carbon oxygen single bond, um isn't really gonna show up, But we will get that strong characteristic Carbonell Peak. Um, right around 1700. So we'll see one signal of interest here right around 1700. And that's how we would be able to tell that this is an Esther. Um, and so this third molecule, uh, the functionality of interest is gonna be the alcohol. Um, and so this is gonna be ah, broad peak between roughly 3200 and 3600 wave number. Um, and that is again gonna be due to this. Uh oh. H and so that's That's how we would tell. So if we see one peek on Lee between 32 3600 we would know that we have the third molecule. One peek on Lee. Um, around 1700. We know that we have the Esther. Ah, and if we see two peaks one and roughly each of those regions. So again, right around 1700 for the carbon Neil. Um, and then maybe maybe a little lower than the alcohol's 253,500 for the O. H of a carb oxalic acid. And so that's how we would sell that. We have the first molecule. Ah, and so that's Ah, that's the answer here. We just need to know that different functionalities air going to give us different I our signals. Ah, and that's the answer to Chapter 19. Problem number seven.