What is the correct order of boiling point for the alkyl halide?

\(C_2H_5I > C_2H_5Br > C_2H_5Cl\)

The correct order of boiling points for the alkyl halides is (2) \(C_2H_5I > C_2H_5Br > C_2H_5Cl\)

The boiling point of an alkyl halide depends on the size of the alkyl group and the type of halogen atom. In general, alkyl halides with larger alkyl groups have higher boiling points. This is because the larger alkyl groups have more electrons, which interact with the electrons of the halogen atom and increase the strength of the C–X bond.

The halogen atoms also have an effect on the boiling point of an alkyl halide. The halogen atoms with larger atomic radii have weaker C–X bonds and therefore lower boiling points.

In the case of the alkyl halides in question, the size of the alkyl group is the same, so the order of boiling points is determined by the size of the halogen atom. The iodine atom has the largest atomic radius and therefore the weakest C–X bond, so \(C_2H_5I\) has the lowest boiling point. The bromine atom has a smaller atomic radius and therefore a stronger C–X bond, so \(C_2H_5Br\) has a higher boiling point than \(C_2H_5I\). The chlorine atom has the smallest atomic radius and therefore the strongest C–X bond, so \(C_2H_5Cl\) has the highest boiling point of the three compounds.

The boiling points of the three compounds are as follows:

• \(C_2H_5I\): 150 °C
• \(C_2H_5Br\): 131 °C
• \(C_2H_5Cl\): 120 °C