2 H-NMR Spectrum Q's

[MordorFires02]

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I've got two quick questions about NMR.

First, pretty simple but just checking to make sure, I'm aware the split for an NMR peak is n+1, regardless of whether the neighbors are equivalent or not. So the CH2 in propane shows up as a septet. But for the integration ratio, it is taken as the total ratio and reduced to the simplest ratio, correct? So for propane, there would be a ratio of 6 (CH3s) : 2 (CH2) and it would be reduced and presented as 3H:1H?

Second question, a bit more obscure. In the first Berkeley Review Ochem book, I was getting to the examples for NMR. In examples 2.20 and 2.23, there are squiggly lines above the peaks that I have not seen before. I tried looking it up and I believe they are related to the integration ratios but I honestly cannot figure it out. Any enlightenment would be greatly appreciated.

Thanks.

 

[vsl5]

I've got two quick questions about NMR.

First, pretty simple but just checking to make sure, I'm aware the split for an NMR peak is n+1, regardless of whether the neighbors are equivalent or not. So the CH2 in propane shows up as a septet. But for the integration ratio, it is taken as the total ratio and reduced to the simplest ratio, correct? So for propane, there would be a ratio of 6 (CH3s) : 2 (CH2) and it would be reduced and presented as 3H:1H?

Second question, a bit more obscure. In the first Berkeley Review Ochem book, I was getting to the examples for NMR. In examples 2.20 and 2.23, there are squiggly lines above the peaks that I have not seen before. I tried looking it up and I believe they are related to the integration ratios but I honestly cannot figure it out. Any enlightenment would be greatly appreciated.

Thanks.

yes to your first question since the hydrogens of each CH3 group on propane are chemically equivalent and will have the same chemical shift. I think it can appear as 6:2 or 3:1.