Extraction Technique (Orgo)

[Hemichordate]

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So on the 4th 30 minute EK Orgo Exam, I came across this question:

#86: In the first extraction, the aqueous layer will be:
a) below the organic layer because it has lower density than organic layer
b) below the organic layer because it has higher density than organic layer
c) above the organic layer because it has lower density than organic layer
d) above the organic layer because it has higher density than organic layer

I put B. In the lecture on extraction, there was a clear diagram labeling the aqueous layer BELOW the organic layer.

However, the answer was C. The explanation was that "From the table, we see that diethyl ether has greater density than water, which will make it sink. However, this is NOT always true for extrations. Sometimes the aqueous layer is heavier". Whaaat?

Can someone explain? What am I missing?

 

[matth87]

Diethyl ether will remain in the organic layer. In this case diethly either has a greater density then what ever you have in the aqueous layer.

The last sentence of the solution is reminding you that if some other substance was left in the organic layer that wasn't diethyl ether the location of that layer relative to the aqueous layer would be based on the denisty.

Its just trying to remind you that different solutions have different densities and the locations of the layers will depend on those densitys so make sure to check the charts you are given.