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Halogenoalkanes

Pebbles47

why are halogenoalkanes more reactive than alkanes? also why do they have higher boiling points?

Reply 1

charco

Study Forum Helper

Original post by Pebbles47

why are halogenoalkanes more reactive than alkanes? also why do they have higher boiling points?

1. They have a functional group (the halogen) that distorts the electron distribution in the molecule making it susceptible to attack by reagents.

2. The polarity makes intermolecular forces stronger.

Reply 2

Swissblade

Original post by Pebbles47

why are halogenoalkanes more reactive than alkanes? also why do they have higher boiling points?

They have polar bonds

C^{\delta ^{+}}-X^{\delta ^{-}}

, where

X

is a halogen, hence have permanent dipole-dipole forces. Alkanes don't have polar bonds therefore only have weak van der Waals forces between them.

(edited 6 years ago)

Reply 3

Nuha.R

Original post by Pebbles47

why are halogenoalkanes more reactive than alkanes? also why do they have higher boiling points?

Haloalkanes generally have a boiling point that is higher than the alkane they are derived from. This is due to the increased molecular weight due to the large halogen atoms and the increased intermolecular forces due to the polar bonds, and the increasing polarizabilty of the halogen.
they are more reactive because as you go down the group reactivity increases i.e. the weaker the bond the lower the activation energy and hence, faster the reaction. R-I>R-Br>R-Cl
hope your Q is answered...