Summary AQA A level chemistry halogenoalkanes full revision notes

Halogenoakanes
13.1 HALOGENOALIKANÉS, 13. 2 NäCLEOPHILI SU8STITUTION

Halogenoalkanes have an alkane skelelon with one or more haloqen atos in place
af hycogen atomns GeneralLfomula: CnHant X

lhe C-X bond IS polar - X* Haloqens are more eletroneaatue than cotbun.
Down the yroup. the bonds qet les po loc
Halogenoalkanes ore not soluble n water. The man ntermolecu lar forces are
dipole- dipole attrachons and Van der Waas focces.
The m\x with hydocacbons So (an be used as dry- leaning fluds

Boling pint ncreases withncreased chan length
Balung point increases goung down the halogen group
large molecules, lacqer number of electrons, 4reate Van de Waals.

inihen halogencalkanes react, the (- Xbond breaks
-X bond entlhaley
Bond enthalpyis a more wmportant factor than hond polants
Nucleophlic subst1tution!
A nucleophile s an electron donOr that danates its lone pair to foom aband.
They have a negatve chage
-hydroxde :OH
cyan1de
annmona NH,

Ihe nuceoph1le replaces the haloqen ina halogencalkane i
Nu

’ R-C- Nu +



H


R-x oH’ ROH X foems an alcohol)
R-Xt cN ’R-(EN + X forms a nitale)
R-X 2Nt, ’ RNH, NH, X (fors amne)
NH

+X
R-c-N-H + NH