[fc3stud]

One of my brainy back-row girls asked why, since glycerides won't dissolve in water, a polar molecule, they will dissolve in halogenoalkanes and ethers.  Is it because they are larger molecules?  Any answers gratefully received. Andrew Walker

[Equi]

Ether and halogen-alkanes don't have that many hydrogen-bond donors/acceptors as water. Therefore the enthalpic energy stays approx. the same, unlike in water, which is not satisfied an forms regular cages (entropy rises, gibbs free energy becomes positive, no disolving).

Naturally, the higher the alkane part in the ether/halogen-alkane the higher the solubility (van der Waals interactions).

[FeLiXe]

the simple explanation is: "like dissolves like"

fats that are only slightly polar will dissolve best in solvents that are only slightly polar, like ether and halogenalkanes