Sorry for being late guys, hahah... Been busy with valentine and stuff. Lul.
So far, we got to name alkanes which had single carbon chains. Now, let's deal with something more complex.
Here we don't have a single carbon chain, it starts to branch off. I went ahead and counted how many carbons there are in a single chain.
So what we do is look at the longest chain. In this case, it's the nice purpley chain. Think of it like the backbone of our naming.
Hence, we have nine carbons \(\Rightarrow\) we're dealing with a nonane! Non for nine and ane because we're dealing with an alkane (we have all single bonds).
What's kind of sticking off our main carbon chain? It's another carbon (w/ three hydrogens)! True?
Maybe you might be tempted to say methane, but no... It's attached to other things. But it would be right to use the prefix: meth.
And we (IUPAC) made it so that it would be called methyl. The yl from methyl means it branches off a longer chain.
Thus, let's call it... methylnonane, but there's one problem. This, however...
This is also methylnonane, true?It goes according to what we did so far.
What about this?. And so on and so forth.
So how would you name those things differently? The way we do that is, number the carbons on your main chain, then look at which carbon # it is bonded to.
Our first molecule, the methyl group is with the third carbon on the main chain. Hence, we call this... 3 - Methylnonane.
What about this?, this would be called 4 - Methylnonane.
And you can try naming the last one. Hahha.