Among the following, which alkyl halide has the highest boiling point?

RI

The correct answer is Option (1) → RI

The boiling point of alkyl halides depends mainly on the strength of intermolecular forces, particularly van der Waals forces (dispersion forces).

These forces increase with:

• Increase in molecular mass

• Increase in size and polarizability of the halogen atom

As we move down the halogen group in the periodic table:

F < Cl < Br < I

The atomic size and number of electrons increase, which increases polarizability and dispersion forces. Stronger intermolecular forces require more energy to separate molecules, leading to higher boiling points.

Thus the boiling point order of alkyl halides is:

RF < RCl < RBr < RI

Therefore, alkyl iodide (RI) has the highest boiling point.