Question

Arrange the following compounds in increasing order of their solubilities in chloroform:
NaCl, CH₃OH, cyclohexane, CH₃CN

• A. NaCl < CH₃CN < CH₃OH < Cyclohexane
• B. CH₃OH < CH₃CN < NaCl < Cyclohexane
• C. NaCl < CH₃OH < CH₃CN < Cyclohexane
• D. Cyclohexane < CH₃CN < CH₃OH < NaCl

Answer 1

The Correct Option is A

Chloroform (CHCl₃) is a polar organic solvent. The general principle "like dissolves like" applies here. Polar substances tend to dissolve in polar solvents, and nonpolar substances tend to dissolve in nonpolar solvents.

NaCl: Sodium chloride is an ionic compound. Ionic compounds are generally not soluble in organic solvents like chloroform.

CH₃OH (Methanol): Methanol is a polar molecule due to the presence of the highly electronegative oxygen atom and the polar O-H bond. It can form hydrogen bonds, but the overall polarity is less than NaCl. Methanol exhibits some solubility in chloroform.

CH₃CN (Acetonitrile): Acetonitrile is a polar molecule due to the CN bond. It is less polar than methanol and has a smaller dipole moment. It will be more soluble in chloroform than NaCl but less soluble than methanol.

Cyclohexane: Cyclohexane is a nonpolar molecule. Chloroform has a dipole moment, so it's considered a polar solvent, although it's not as polar as water or methanol. Cyclohexane will be the most soluble in chloroform among the given options because chloroform's polarity is relatively low within the spectrum of polar solvents.

Therefore, the increasing order of solubility in chloroform is: NaCl $<$ CH₃CN $<$ CH₃OH $<$ Cyclohexane.