Esters' high boiling point

[Shyanne]

Why does 3-methylbutyl ethanoate have a higher boiling point than 3-methylbutan-1-ol and ethanoic acid?

Attempt at a solution: I know that the ester has a marginally greater molar mass but I wasn't sure if this is the only deciding factor, particularly considering the strength of the other interaction forces between alcohol and carboxylic acid molecules.

 

[Zypheros_Knight]

I can't give you the exact answer because of the rules but I can tell you this...it has something to do with intermolecular forces of attraction and this link may help you.

 

[Shyanne]

I can't give you the exact answer because of the rules but I can tell you this...it has something to do with intermolecular forces of attraction and this link may help you.

I understand that intermolecular forces of attraction are stronger in alcohol and carboxylic acid but it doesn't make sense then that the ester would have a higher boiling point?

 

[Zypheros_Knight]

I understand that intermolecular forces of attraction are stronger in alcohol and carboxylic acid but it doesn't make sense then that the ester would have a higher boiling point?

The intermolecular forces do not depend entirely on the ability of a molecule to make hydrogen bonds.

 

[Shyanne]

The intermolecular forces do not depend entirely on the ability of a molecule to make hydrogen bonds.

So would I be correct in saying that the ester's boiling point is slightly higher due to its larger molar mass?

 

[Zypheros_Knight]

So would I be correct in saying that the ester's boiling point is slightly higher due to its larger molar mass?

Yes :)...and remember this 3-methylbutyl ethanoate has a higher density than both ethanoic acid and 3-methylbutyl-1-ol, thus it is easy to say it will have a higher b.p cause of that and beacuse the induced dipole-induced dipole forces are greater.

 

[snorkack]

Hm... let´s compare various simple compounds with 6 heavy atoms.
Hexane, C₆H¹⁴: n-hexane 69 degrees, isomers less, down to neohexane, 50 degrees.
Pentanols, C₅OH₁₂: 1-pentanol 138 degrees, isomers less, down to tertiary pentanol, 102 degrees.
Ethers C₅OH₁₂: methyl tert-buthyl ether 55 degrees
Aldehydes C₅OH₁₀: n-pentanal 102 degrees
Ketones C₅OH₁₀: 2-pentanone 102 degrees, 3-methyl-2-butanone 92 degrees, 3-pentanone 101 degrees
Acids C₄O₂H₈: n-butyric acid 164 degrees, isobutyric acid 155 degrees
Esters C₄O₂H₈: ethyl acetate 77 degrees