[qazwsx]

Hey

I'm doing a lab on the esterification of banana oil. It says to first reflux the reaction of isoamyl alcohol + acetic acid with catalytic H2SO4. After the reaction has proceeded, it is to be cooled and added to water, after which it will form separate organic and aqueous layers. I know that the ester (isoamyl acetate/banana oil) is located in the organic layer, and i know that the H2SO4 and excess acetic acid will be in the aqueous layer.

But my question is, do acetic acid and H2SO4 dissolve in BOTH the aqueous and the organic layers? i.e. does the isoamyl acetate actually dissolve some of the acetic acid and sulfuric acid, even though the majority of the acid would be in the aqueous layer?

I'm trying to find the distribution of their solubilities between water and isoamyl acetate, but I'm not having much luck. Any help would be much appreciated!

[fledarmus]

The sulfuric acid will definitely not dissolve in the banana oil, and if any acetic acid does, it will only be a trace. The largest contaminant in your oil is likely to be traces of water.

[qazwsx]

Thanks for the reply

However, the next part of the lab involves isolating the organic layer, and then washing the organic layer with sodium bicarbonate solution.

If it is true that there is no acid in this layer, then what is the point of this wash? I assumed it was to neutralize the organic layer and remove any left over acid... so basically the point of this step is to remove the traces of acetic acid dissolved in banana oil?

Thank you for your help
 

[fledarmus]

Exactly. The esterification reaction is an equilibrium reaction - if there is acid and water remaining in your ester, it will slowly hydrolyze back to the alcohol and carboxylic acid.