alo alkanes
alkanes with 1 or more halogens attached to it
naminghalogeno alkanes
1 find longest carbon chain forms last partof name
2 names and positionsof halogenon molecules comes first prefix
prefixes fluoro chloro bromo iodo
use numbers to state their positions on carbon chain
must be in alphabetical order if more than 1 typeofhalogen
3 more than one of the same typeof halogen prefix with di tri tetra
e's
H
É Ice 1 bromo 1,1 dichloro 2 iodo ethane
boiling point trends ofhalogenoalkanes
b p increases down group
strengthof intermolecular forcesgovern the b p strongerthe
ee higherthe b p intermolecular
As youdescendgroup 7 no of e increases
more e means stronger van der waals forces betweenmoleculesand so
more energyneeded to overcome these forces b p increases down the group
Bond polarityandnucleophiles
halogens are more electronegative than carbon so pull e towards themserve
a covalent bond leads to a polar bond
e 91
HE É
polar bond means that theycan be attacked by nucleophiles
nucleophile a substance that is an e pair donor
eg CN NH3 OH
reaction with hydroxide ions overall equation R X NaOH ROH Nay
via nucleophilic substitution i R
alkylgroup X halogen
conditions
I Grano9989888SEE hydroxide sourceof ions
on
hot formed
ii
gtfo É n
I
n
reaction with cyanide ions
5
overall equation R X KIN Rent KX
via nucleophilic substitution 1 R alkylgroup X halogen
conditions
1 warm ethanolic potassiumcyanide source of CN ions
carried out under REFLUX
nitrileformed
Ekg n
reaction withammonia
n
g
c
overallequation H3CH2CH2NH3 CHzCHzNHz Nagel
via nucleophilic substitution
conditions
1 Heat with ethanolicammonia
2 Must have excess ammonia r amine formed
Ets
Eas ftp.t.IE
nucleophile 5baseiiitiI
t
acts as a
alkanes with 1 or more halogens attached to it
naminghalogeno alkanes
1 find longest carbon chain forms last partof name
2 names and positionsof halogenon molecules comes first prefix
prefixes fluoro chloro bromo iodo
use numbers to state their positions on carbon chain
must be in alphabetical order if more than 1 typeofhalogen
3 more than one of the same typeof halogen prefix with di tri tetra
e's
H
É Ice 1 bromo 1,1 dichloro 2 iodo ethane
boiling point trends ofhalogenoalkanes
b p increases down group
strengthof intermolecular forcesgovern the b p strongerthe
ee higherthe b p intermolecular
As youdescendgroup 7 no of e increases
more e means stronger van der waals forces betweenmoleculesand so
more energyneeded to overcome these forces b p increases down the group
Bond polarityandnucleophiles
halogens are more electronegative than carbon so pull e towards themserve
a covalent bond leads to a polar bond
e 91
HE É
polar bond means that theycan be attacked by nucleophiles
nucleophile a substance that is an e pair donor
eg CN NH3 OH
reaction with hydroxide ions overall equation R X NaOH ROH Nay
via nucleophilic substitution i R
alkylgroup X halogen
conditions
I Grano9989888SEE hydroxide sourceof ions
on
hot formed
ii
gtfo É n
I
n
reaction with cyanide ions
5
overall equation R X KIN Rent KX
via nucleophilic substitution 1 R alkylgroup X halogen
conditions
1 warm ethanolic potassiumcyanide source of CN ions
carried out under REFLUX
nitrileformed
Ekg n
reaction withammonia
n
g
c
overallequation H3CH2CH2NH3 CHzCHzNHz Nagel
via nucleophilic substitution
conditions
1 Heat with ethanolicammonia
2 Must have excess ammonia r amine formed
Ets
Eas ftp.t.IE
nucleophile 5baseiiitiI
t
acts as a
