Question

In the extraction of trimyrisitn from nutmeg:

Why was diethyl ether used as the extraction solvent instead of using acetone directly, since you were going to recrystallize using acetone anyway

How would your results be different (if at all), if the reflux was only done for 10 minutes? Briefly explain

Why is the technique of reflux generally used in organic chemistry

Answer 1

first i will answer to ur last question ..dat why reflux is generally used in oc

Many organic reactions are quite slow and need heating to achieve a reasonable reaction rate. However, most organic chemicals are quite volatile, and if heated they will evaporate and be lost. The solution to this problem is to heat the reaction mixture under reflux.

This involves having the reaction mixture in a flask which is attached to a vertical, open Liebig condenser. Never attempt to stopper the Liebig condenser. This is quite a popular idea among students "to stop the vapour escaping". If you attempt to heat sealed glass apparatus it may explode! There should be no problem with vapour escaping - as it hits the cold surface of the condenser it will condense and drip back in to the flask.

Nutmeg, another solid, is a spice native to the Spice Islands and contains several components including cellulose, fats and essential oils. One of those fats found in nutmeg is trimyristin, which can be isolated from nutmeg through extraction with dichloromethane and diethyl ether. .

Diethyl ether was chosen as the solvent because it is less polar than acetone. Overall, diethyl ether has no dipole moment because the dipoles of the O-C bonds are equal and opposite, so they cancel each other out. However, the bonds between the oxygen and carbon atoms are polar, giving the molecule some polar character. The trimyristin molecule also has polar components, but overall, there is much more of the molecule that is nonpolar. Acetone, conversely, is a polar molecule, with an overall dipole moment. Since like dissolves like, the diethyl ether will dissolve the trimyristin, while the acetone will not. In the reaction vessel, the diethyl ether serves as a solvent, removing the trimyristin from the nutmeg in the solution.

The oil that was extracted from the nutmeg was impure because the diethyl ether would pull out more than just the desired product. The organic solvent will pull many nonpolar molecules out of the nutmeg, but the trimyristin was the component that should have re-crystallize with the addition of the acetone. The acetone is a polar solvent, so it dissolved the polar impurities in the oil and the nonpolar component, trimyristin, crystallized out of the solvent.

if reflux will be for les time i guess we will get less quantiy of the desired product