Give the IUPAC names for the following alkanes: ...

Question

Give the IUPAC names for the following alkanes:

Accepted Answer

All right. Hi, everyone. So for this question, lets provide the Iupac name of the A canine represented by the model. Option A says two methyl hept. Option B says three isopropyl pentane. Option C says three ethyl, two methyl pentane and option D says three ethyl hexane. So in this case, recall that carbon atoms are represented by the blue spheres in the model, whereas hydrogen atoms are represented by the white spheres. Now, when it comes to the Iupac naming based on a model, I actually prefer to find the line or skeletal structure first because this is only an arcane, there are only going to be carbon and hydrogen atoms present in this molecule. So by drawing the line structure first, we can only go ahead and focus on the carbon atoms as opposed to the hydrogens which are implied in line structures. So first, I would go ahead and find the parent chain which is the longest continuous chain of carbons present in the molecule. Now, after trying out various different combinations, I can see that the longest carbon chain is five carbons. Not now just for the record, there are multiple ways that you can number a five carbon chain in this molecule. But regardless, you should still get the same molecule, right. So because my longest carbon chain is five carbons, I'm first going to go ahead and draw a line with a total of five corners and open ends because recall that in a line structure corners and open ends represent carbon atoms. So at this point, I would go ahead and match all substituents branching from the carbon chain. On position two, I have one other carbon branching out of the parent chain. Whereas on carbon three, I have two carbons branching out. So now I can go ahead and proceed with my Iupac name. The first step if you recall is to go ahead and identify and name your parent change as we discussed earlier, right, the longest continuous chain of carbons was five carbons long. So the parent name is therefore going to be painting because again, this is an all right. So now I can go ahead and proceed with naming substituents that are branching out of the parent chain. Now, in this case, I only have two because if I number my parent chain one through five, I have two groups branching out of it. Now, one of them is composed of only one carbon. If I scroll down here, one carbon and three hydrogen atoms, which if you recall is referred to as a metal group. Now, the other substituent is composed of one CH two and ach three connected together in a straight chain. And because that substituent is two carbons long, we refer to it as an EO group. But recall also that it's not enough to simply state what type of constituent we have, right? We must specify their position on the parent chain with a number. So when it comes to numbering the parent chain, the reason why I decided to number my carbons one through five from left to right was because the left side of the molecule was the one closest to the closest substituent. So that ensures that substituents are given the smallest position number possible. So based on this, I can build on my substituent names a little bit instead of saying simply methyl, I would specify that the methyl group is on carbon two of my parent chain. So that becomes two dash metal or two metal as it's read. On the other hand, on carbon three here, I've got the EO group. So instead of saying simply Ethel, I would say three dash Ethel. So now in my parent or my Iupac name, I would arrange my substituent names in alphabetical order, followed by the name of the parent chain with no spaces in between them. So because the E in Ethel goes before the M in methyl, I would place my EO group first. So thats three dash Ethel dash two dash metal panting once again with no spaces in between them. But notice how dashes are used to separate numbers from letters. So after all is said and done, my final Iupac name is three ethyl, two Methyl painting, meaning that my answer is going to be option C in the multiple choice and there you have it. So with that being said, thank you so very much for watching and I hope you found this helpful.

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Give the IUPAC names for the following alkanes: <IMAGE>

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