Consider the following organic substances: ethylethanoate, ethylmethylether, hexanol, and propanone. (a) Which of these molecules contains three carbons?

Video transcript

hey everyone in this example we need to determine which of the following molecules contains four carbons metal method. Oh wait one at oxy butane, one propane all or to pentagon. So to draw out our molecules beginning with methyl method. Oh wait we're going to have a carbon heel group where we have a carbon double bonded to an oxygen atom also bonded to a hydrogen and then bonded to a second oxygen atom. Where this oxygen atom is bonded to a methyl group. So this is our metal method await. We then have for our molecule one at Toxie butane. We'll start with an oxygen atom that is bonded to two ethyl groups. So that would be two carbons that are bonded to two hydrogen and then we have another carbon bonded to another carbon here giving us a methyl group at the end. So we have two methyl groups. And again these carbon atoms are bonded to two hydrogen atoms which we don't really have to draw in. It's just interpreted. So they're stable and have four bonds and we have CH two. That is considered an ethyl group. And that is why we have our oxygen between these two ethyl groups. And when we have the suffix butte here that tells us that we have four carbons. However counting the carbons in our metal groups in this molecule, we would have a total of 123456 carbons total. So we would say we have six carbons here whereas in our first molecule we have a total of just 12 carbons. So so far we can rule out these molecules as having four carbons. Moving on to our next type of molecule, we have the molecule one professional. So we have a alcohol group bonded to our first carbon here because we want substitutes to be at the lowest numbered carbon. And then because we have the prefix prop that tells us that we have three carbons. So this carbon is bonded to another carbon which is bonded to a methyl group And this is our one professional. And so as we counted we have a total of 123 carbon atoms here. So moving on to our last molecule, we have to Penton on. So to draw to Penton in we have a methyl group which is bonded to another carbon that is double bonded to an oxygen atom. Where now this carbon is bonded to a second carbon chain which goes on and ends here. So here we have a CH three group or mental group. Our prefixed Pent tells us that we have five carbons and if we count we have a total of 12345. So we know we have the proper molecule for five pentagon. Okay, and again we stated that or sorry this would be to pentagon and we stated that Pent tells us that we have five carbons. So we can already roll this out because we have five carbons in this molecule and so we would say that therefore none of the molecules Have four carbons as our final answer. So this would be our final answer. To complete this example. If you have any questions, please leave them down below. Otherwise, I'll see everyone in the next practice video.