Naming components of an ester Watch

User947387
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I was told that in order to name an ester from a shortened structural formula, you drew out the full structural formula, find the ester link; draw a line which splits the link and then the half that contains the O-C bond belongs to the alcohol, meaning you count the carbons contained there; and then name it accordingly.

The half which contains the C=O bond is for the acid; and again, you count the carbons, name it accordingly.

With that in mind, I identified that the answer was B; the alcohol was propanol and the acid was ethanoic acid.

However, the answer given as A; i.e. the alcohol is Ethanol and the acid is butanoic acid.
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Dylann
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Ester A (ethyl butanoate) contains 6 carbon atoms.
Ester B (propyl ethanoate) contains 5 carbon atoms.

So there must be an issue with the "shortened structural formula" and the "full structural formula" - because they're quite different compounds.

Also, I would refrain from talking about the O-C bond since there are two O-C bonds in any ester.

(Original post by apronedsamurai)
I was told that in order to name an ester from a shortened structural formula, you drew out the full structural formula, find the ester link; draw a line which splits the link and then the half that contains the O-C bond belongs to the alcohol, meaning you count the carbons contained there; and then name it accordingly.

The half which contains the C=O bond is for the acid; and again, you count the carbons, name it accordingly.

With that in mind, I identified that the answer was B; the alcohol was propanol and the acid was ethanoic acid.

However, the answer given as A; i.e. the alcohol is Ethanol and the acid is butanoic acid.
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User947387
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Ok, so in the question I uploaded; has the shortened structural formula or the full formula been used?
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charco
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(Original post by apronedsamurai)
Ok, so in the question I uploaded; has the shortened structural formula or the full formula been used?
I see no question ... :dontknow:
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User947387
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Sorry thought it had attached
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Dylann
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(Original post by apronedsamurai)
Sorry thought it had attached
So there are four carbons including the C=O on the left which means the acid has four carbons so it's butanoic acid

There are two carbons on the right of the O=C-O bonds so that's your alcohol....ethanol

The acid will always have a C=O group (carbonyl) so look at all the carbons including the carbonyl carbon joined to it, usually diagrammatically on the left of the compound.

A simpler way might be to just identify the ester link -O- the carbons on the side with C=O are the acid and carbons on the other side are the alcohol

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