Question

Assertion: The boiling points of alkyl halides decrease in the order:

RI > RBr > RCl > RF

Reason: The boiling points of alkyl chlorides, bromides and iodides are considerably higher than that of the hydrocarbon of comparable molecular mass.

Options

• Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

• Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

• Assertion (A) is true, but Reason (R) is false.

• Assertion (A) is false and Reason (R) is true.

Answer 1

Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).

Explanation:

For an identical alkyl group, the boiling points of haloalkanes diminish in the following sequence:

RI > RBr > RCl > RF

This is because Van der Waals forces rise in tandem with the mass and size of the halogen atom. Alkyl halides have a greater boiling point than hydrocarbons with comparable molecular weights because they are polar, whereas hydrocarbons are not.