Jshek
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I need help urgently I dont get any of this. Please guide me through the questions
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Jshek
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Kallisto
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What exactly didn't you understand and why do you need help to solve these questions?

To 4:
Butanal is an aldehyde. Do you know the functional group of this organic substance?

To 5:
pentanoic acid is a carboxylic acid. Can't you guess the functional group out?

To 6:
It is an alkene. Do you know the difference between an alkane and alkene? clue: it has to do with a bond. On which carbon atoms can be this bond? name the position of this bond and thus the isomers.

To 7:
That is a halogenalkane, so an alkane with chlorine on it to be exact. On which carbon atoms can this chlorine be placed?

To 8:
Halogenalkane again, but with two bromine atoms as halogen this time. How can those two be distributed on the chemical structure? on which carbon atoms they can be bonded?
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Jshek
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(Original post by Kallisto)
What exactly didn't you understand and why do you need help to solve these questions?

To 4:
Butanal is an aldehyde. Do you know the functional group of this organic substance?

To 5:
pentanoic acid is a carboxylic acid. Can't you guess the functional group out?

To 6:
It is an alkene. Do you know the difference between an alkane and alkene? clue: it has to do with a bond. On which carbon atoms can be this bond? name the position of this bond and thus the isomers.

To 7:
That is a halogenalkane, so an alkane with chlorine on it to be exact. On which carbon atoms can this chlorine be placed?

To 8:
Halogenalkane again, but with two bromine atoms as halogen this time. How can those two be distributed on the chemical structure? on which carbon atoms they can be bonded?
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would this be correct (i dont know if my drawing are right)
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Jshek
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(Original post by Jshek)
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would this be correct (i dont know if my drawing are right)
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Deggs_14
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That’s not pentanoic acid you’ve drawn that’s propyl ethanoate which is an ester, which works as a functional group isomer. The carboxylate group is always at the end of the chain so you don’t number it’s position.
Last edited by Deggs_14; 3 months ago
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Deggs_14
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A chain isomer of pentanoic acid would be methylbutanoic acid or dimethylpropanoic acid - label with carbon atoms the methyl groups are on eg 2-methylbutanoicacid, numbering from the carbon of the carboxylate ion as carbon 1.
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Jshek
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(Original post by Deggs_14)
That’s not pentanoic acid you’ve drawn that’s propyl ethanoate which is an ester, which works as a functional group isomer. The carboxylate group is always at the end of the chain so you don’t number it’s position.
I'm confused because pentanoic acid is C5H10O2 which is what I drawer
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Kallisto
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(Original post by Jshek)
I'm confused because pentanoic acid is C5H10O2 which is what I drawer
The aldehydes in 4a) and 4c) are wrong too. There is no Aldehyde group (-CHO) drawn for this kind organic substance. And as it is written above, pentanoic acid as a carboxylic acid has a carboxyl group (-COOH), that is what can't be seen in your sketch.
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Jshek
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(Original post by Kallisto)
The aldehydes in 4a) and 4c) are wrong too. There is no Aldehyde group (-CHO) drawn for this kind organic substance. And as it is written above, pentanoic acid as a carboxylic acid has a carboxyl group (-COOH), that is what can't be seen in your sketch.
For 4a I have C double bond O and H which gives me COH right?
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Jshek
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(Original post by Kallisto)
The aldehydes in 4a) and 4c) are wrong too. There is no Aldehyde group (-CHO) drawn for this kind organic substance. And as it is written above, pentanoic acid as a carboxylic acid has a carboxyl group (-COOH), that is what can't be seen in your sketch.
I've drawn C double bond O single bond O and H at the end of pentanoic acid which gives me COOH? What am I doing wrong?
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Kallisto
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(Original post by Jshek)
I've drawn C double bond O single bond O and H at the end of pentanoic acid which gives me COOH? What am I doing wrong?
The functional groups are on the first C-atoms:

For the -CHO on aldehydes, an O double bond and an H are connected on this C atom.

For the -COOH in carboxylic acid, an O double bond and -O-H bond is on the first C-atom connected.

Both are not drawn in your sketches.
Last edited by Kallisto; 3 months ago
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Jshek
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(Original post by Kallisto)
The functional groups are on the first C-atoms:

For the -CHO on aldehydes, an O double bond and an H are connected on this C atom.

For the -COOH in carboxylic acid, an O double bond and -O-H bond is on the first C-atom connected.

Both are not drawn in your sketches.
Like that
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Kallisto
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(Original post by Jshek)
Like that
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Send you some links to aldehyde and carboxylic acid. Look at them and compare.

Aldehyde
http://www.u-helmich.de/che/EF/atom/.../aldehyd01.jpg

R stands for the chain length of hydrocarbons

Carboxylic acid
https://upload.wikimedia.org/wikiped...re_V.1.svg.png

The same here: R is the chain length of hydrocarbons.
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