Lithium fluoride (LiF) is an ionic compound, consisting of positively charged lithium ions (Li+) and negatively charged fluoride ions (F-). Cyclohexane, on the other hand, is a nonpolar molecular compound, composed of carbon and hydrogen atoms bonded together covalently.

Due to the fundamental differences in their chemical nature, LiF is not soluble in cyclohexane. Ionic compounds like LiF require polar solvents, such as water, to dissolve. Polar solvents have a partial charge separation, allowing them to interact with and solvate the charged ions of the ionic compound.

In contrast, nonpolar solvents like cyclohexane lack this partial charge separation and cannot effectively solvate ionic compounds. As a result, LiF remains undissolved when mixed with cyclohexane.