Hey everyone. So for this example question, it says, which of the following compounds would you expect to show UV absorptions in the 200 to 400 nanometer range? Alright. So we know that this range ties into UV-Vis spectroscopy, and we know that when we're talking about this topic, it deals with conjugated systems.

So the ones that are conjugated are the ones that could fit within this given range. So, if we take a look at our options, we have pi bond, single single pi bond, or pi bond, single single single pi bond. This is not conjugation, so there's no chance of it falling within this range. For the next one, we have pi bond, single bond, pi bond, single bond, pi bond. So we have a portion of it that's conjugated.

Therefore, it should fall within this range. So this is an answer. For the next one, we have pi bond, single bond. That group there is a nitrile. Remember, nitriles have pi bonds.

It's a carbon triple bonded to nitrogen. So although we can't see it, we need to remember that it would still be pi bond, single bond, pi bonds. So, this would have some level of conjugation, so this would be included. For this one, we don't even need to do much. We can see that there's a benzene ring here, which is a conjugated system.

It's pi bonds and single bonds alternating, so this is another one that fits. Then finally, this last one here we have pi bond, single bond, pi bond, single bond, pi bond. A portion of this molecule is conjugated. Therefore, it could fall within this range. So from our options, we can see that 2, 3, 4, and 5 could be expected to have a value that falls within this given range.

So here, out of our options, it will be answer e. E says 2, 3, 4, and 5. Again, one doesn't work because one is not conjugated at all, so it's not gonna fall within this range. Again, remember, when we're talking about UV-Vis spectroscopy, we're looking at conjugated pi bonds. Where there's conjugation, there's a chance of it falling within these ranges.