Question

Based on solute-solvent interactions, arrange the following in order of increasing solubility in n-octane and explain.

Cyclohexane, $KCl,C{H}_{3}OH,C{H}_{3}CN$

Answer 1

n-Octane is non polar and can dissolve non-polar solutes. It cannot dissolve polar (and ionic) solutes.

$\text{Cyclohexane}$ is non-polar. Hence, easily soluble in n-octane.

$\text{Methanol}$ and $\text{acetonitrile}$ are polar and have very low solubility in n-octane.

$\text{KCl}$ is ionic compound and hence, insoluble in n-octane.

The increasing order for solubility in n-octane is as follows:

$KCl<C{H}_{3}OH<C{H}_{3}CN<\text{Cyclohexane}$