The solubility of ionic compound in nonpolar solvents can be drastically increased by using a class of compounds called

Options

A. crown alcohols
B. crown ethers
C. crown aldehydes
D. crown acids

Answer

2

Explanation

The compound `18-crown-6`, where the number 18 refers to the total number of atoms in the ring and 6 to the number of O atoms in the ring, is particularly effective in binding alkali metal ions such as `K^(+)`.
For example, potassium permanganate `(KMnO_(4))`, which is practically insolube in benzene, can be made to dissolve to a certain extent in that solvent if a suitable crown ether (the three-dimensional structure of the molecule resembles a crown and hence the name of this class of compounds) is added to it. The cation is held in the centre of the ring by ion-dipole interaction with the surrounding O atoms.
Because the exterior of the crown ether is largely nonpolar, the crown ether `-K^(+)` unit can readily dissolve in nonpolar solvents. The resulting solution is useful because it allows oxidation with `KMnO_(4)` to be carried in nonpolar organic solvents.