Question

Why is acetone the best solvent for the reaction between alkyl chloride and potassium iodide?
A. Alkyl iodide is insoluble in acetone
B. Alkyl chloride is less soluble in acetone
C. KCl has a higher dipole moment than KI
D. KCl is not soluble in acetone

Answer 1

Hint: Alkyl chloride is basically an organic compound, covalent in nature. On the other hand, potassium iodide. Due to polarisability of iodide ion it also has covalent character. Acetone is also covalent, organic compound.

Complete step by step answer:
In case of acetone due to presence of carbonyl group it has a dipole moment. Due to its dipole nature it is called polar solvent. It can dissolve other polar compounds of organic compounds.
In the reaction of alkyl chloride and potassium iodide substitution of chlorine atom by iodine takes place, and alkyl iodide is formed with a side product potassium chloride.
The reaction is shown below,
\[{\text{R - Cl + KI}} \to {\text{R - I + KCl}}\]
In the product the solubility of potassium chloride in acetone is very less. Due to this reason separation of potassium chloride from the desired product is very easy for this reaction.
Due to this reason acetone is used as solvent for this reaction.

Hence option D is correct.

Note:
Solubility takes the place of compounds that have similar polarities like the solvent in their molecules. Polar molecules dissolve in polar solvents and nonpolar molecules dissolve in nonpolar solvents. If we place a solid which is nonpolar into a nonpolar liquid, then "like dissolves like'' implies that the solid will dissolve in the given liquid.