The Student Room Group

chemistry help needed please :)

Tried for soo long, please give an explanation if that's ok please

A compound, X, reacts with the product of its
own oxidation to form an ester.
X could be
A propanal
B propan-1-ol
C propan-2-ol
D propanoic acid.
X has to be a primary alcohol, as it has been oxidised (under reflux) to produce a carboxylic acid which it reacts with to produce an ester.
Reply 2
so propan-1-ol, B
Original post by PLM98
so propan-1-ol, B


Propanal can also be further oxidised to a carboxylic acid though
Yes so the alcohol reacts with the carboxylic acid to form the ester....
Reply 5
Original post by Nucleotide
Propanal can also be further oxidised to a carboxylic acid though


But propanal doesn't react with a carboxylic to form an ester, only an alcohol does. So it must be B.
Original post by Dylann
But propanal doesn't react with a carboxylic to form an ester, only an alcohol does. So it must be B.


I misread the question! That's right
Original post by flyingpanda786
Tried for soo long, please give an explanation if that's ok please

A compound, X, reacts with the product of its
own oxidation to form an ester.
X could be
A propanal
B propan-1-ol
C propan-2-ol
D propanoic acid.


Brother! from your question, the correct answer is propan-1-ol. Firstly, as a primary alkanol, propan-1-ol is oxidized to propanal using acidified potasium tetraoxomanganate(vii) or acidified potassium heptaoxodichromate(vi). Then, propanal is oxidized further to alkanioc acids in the presence of strong oxidizing agents like the ones we mentioned earlier. Esterification is the rxn between alkanioc acids (the oxidation product of primary alkanols) and alkanols. So propan-1-ol can react with its product(alkanioc acids) to form ester.
it can only be propan-1-ol
SOOOO ester is formed by condensation reaction between a carboxylic acid and an alcohol.

Elimination:

propanoic acid can't be oxidised - answer is NOT d

propanal can be oxidised to carb acid, BUT carb acid cannot react with propanal (aldehyde) to form an ester - answer is NOT A

Propan-2-ol is a secondary alcohol...so can only be oxidised to a ketone. Ketone cannot react with carb acid to produce an eseter - answer is NOT C

THEREFORE ANSWER IS B, as propan-1-ol is a primary alcohol which can be oxidised to a carboxylic acid, and carb acid can react with the alcohol to make an ester!

Hope that helped :biggrin: :biggrin:
Original post by Goodbless
Brother! from your question, the correct answer is propan-1-ol. Firstly, as a primary alkanol, propan-1-ol is oxidized to propanal using acidified potasium tetraoxomanganate(vii) or acidified potassium heptaoxodichromate(vi). Then, propanal is oxidized further to alkanioc acids in the presence of strong oxidizing agents like the ones we mentioned earlier. Esterification is the rxn between alkanioc acids (the oxidation product of primary alkanols) and alkanols. So propan-1-ol can react with its product(alkanioc acids) to form ester.


Wow thats an amazing explanation thank you soo much!
Original post by mrchemistry
SOOOO ester is formed by condensation reaction between a carboxylic acid and an alcohol.

Elimination:

propanoic acid can't be oxidised - answer is NOT d

propanal can be oxidised to carb acid, BUT carb acid cannot react with propanal (aldehyde) to form an ester - answer is NOT A

Propan-2-ol is a secondary alcohol...so can only be oxidised to a ketone. Ketone cannot react with carb acid to produce an eseter - answer is NOT C

THEREFORE ANSWER IS B, as propan-1-ol is a primary alcohol which can be oxidised to a carboxylic acid, and carb acid can react with the alcohol to make an ester!

Hope that helped :biggrin: :biggrin:


That really helped soo much, thank you for your time :smile:

Quick Reply

Latest