yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Naming alkanes with ethyl groups | Organic chemistry | Khan Academy


2m read
·Nov 11, 2024

I think we're ready now to tackle some more or even more complicated examples. So let's draw something crazy here. So let's see, let me draw a chain. Let me draw it like that, and so like we've done in all of the examples, you want to find the longest chain.

We could count from here: one, two, three, four, five, six, seven, eight, or maybe it's one, two, three, four, five, six, seven; no, or maybe it's one, two, three, four, five, six, seven, eight, nine, ten. That is our longest chain. Let me just let me make that in green. So our longest chain here is in green.

So this decade, this, sorry, this backbone has 10 carbons in it. The prefix 410 is dec. It is an alkane since it has all single bonds, so we can write decane for the backbone. And then it has a group right here. It has a group right here, and this group consists of one, two carbons attached to the backbone. The prefix for two carbons is f, so this is an ethyl group. The yl is because it's a group attached to the main alkane chain, so we call this ethyl decane.

We have to specify where the ethyl group is attached, and we want to give it as low of a number as possible, so we start counting on the side closest to it. So it's one, two, three, four, five; so this is five ethyl decane. Now let's complicate this a little bit more.

So let me just copy and paste this, copy, and then paste, so I have pasted it there. And let me complicate this molecule a little bit more. Let me add another ethyl group to it. Let me add another ethyl group to it. So let's say we have another ethyl group over there.

Now, what is this going to be? Well, still, the longest chain is still going to be that thing in green, so it's still going to be a decane. It's still going to be a decane, but now we have two ethyl groups: one on the five carbon, one, two, three, four, five, and then one on the six carbon.

So what we write here is you might be tempted to write five ethyl six ethyl decane, which really wouldn't be wrong, but it would just be maybe more letters than you want to write. Instead, you write five, comma, six diethyl decane. The 5, 6 tells us the two carbons on the main backbone that the ethyl groups are attached to, and the di says that we have two ethanes, or two ethyl groups, I should say, not ethane groups; two ethyl groups: one over here and one right over here.

More Articles

View All
Thousands of Cranes Take Flight in One of Earth's Last Great Migrations | National Geographic
[Music] This is, I think, without doubt, one of the most spectacular migrations that you can witness in North America, if not the most spectacular. There’s just something really uplifting and inspiring about them, and people all over the world have felt t…
Why Startup Founders Should Launch Companies Sooner Than They Think
What’s going on is that founders are just, they’re embarrassed about the state of their own product. They’ve come from companies that have mature, polished products, and they compare their launch to like an Apple launch. If Apple fumbles a launch, the wor…
The truth behind jet lag...
The thing that everybody thinks is jet lag. People think it’s because of the time zone change; it really is not the time zone change. It’s the cabin altitude of the plane. If you ever go skiing and you go to a place that’s at 2500 or 3,000 M, and the fir…
Example estimating from regression line
Lizz’s math test included a survey question asking how many hours students spent studying for the test. The scatter plot below shows the relationship between how many hours students spend studying and their score on the test. A line was fit to the data to…
Confucius | The Art of Becoming Better (Self-Cultivation)
Isn’t it the case we should always stay true to ourselves? Which means that we ought to know who we are and organize our lives in ways that are compatible with our personalities? When we look for a partner, for example, we look for someone that we’re comp…
Why YOU Need To Invest in PSYCHEDELICS | Ask Mr. Wonderful #14 Kevin O'Leary
[Music] All right everybody, back for another episode of “Ask Mr. Wonderful.” Here today with my recently acquired 1969 Telecaster. Telecasters are very unforgiving guitars. Not that I want to get sidetracked here, but I just thought maybe a couple of lit…