How many signals would you expect to find and into how many...

How many signals would you expect to find, and into how many peaks will each signal be split of the following compound: 1,1,1-trichloropropane A. 2 signals; from downfield to upfield; triplet, quartet B. 2 signals; from downfield to upfield; singlet, doublet C. 2 signals; from downfield to upfield; quartet, triplet D. 3 signals; from downfield to upfield; quartet, triplet, singlet

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0:00 Right.

00:01 We have got to figure out a likely hnmr signal, essentially, spectrum, for 1 -1 -1 -trichloropropane.

00:10 So here's propane, and here is 111 -trichloropropine.

00:17 Now, let's add in our hydrogens.

00:20 We've got two here, two here, and three here.

00:30 There we are.

00:31 Okay.

00:32 So let's consider, before anything, which of these are going to be furthest downfield? right, which if you recall means most deshielded, least electron density surrounding them.

00:47 Well, recall that chlorines are rather electronegative.

00:50 They pull electron density to them through sigma bonds, right? so there's electron density being pulled through the sigma bonds, and that's going to have a greater effect on these hydrogens that are nearby than these hydrogens that are further away.

01:09 So these protons are going to be the most deshielded and therefore the furthest downfield.

01:16 I'm going to call those protons a, and i'm going to call these protons b.

01:21 So a is going to be downfield.

01:26 Okay.

01:29 Now we need to figure out what their patterns are.

01:32 So recall that to figure out the pattern, we need to know how many neighbors there are, and then we need to add one to that, and that'll tell us how many signals to expect...

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