6.4 Halogenoalkanes Flashcards
Classifying, nucleophillic substitution + mechanism, hydrolysis, reactivity
What are haloalkanes?
Saturated organic compounds that contain carbon atoms and at least one halogen atoms
Are halogenoalkanes soluble in water?
Insoluble as C-H bonds are non-polar, not compensated for enough by C-X bond polarity
Do halogenoalkanes have a polar bond? Why?
Yes polar, as halogen has a higher electronegativity than C (halogen is δ-, carbon is δ+)
What type intermolecular forces do halogenoalkane have? Why?
Permanent dipole-dipole and London forces of attraction
C-X bond polarity creates permanent dipoles
When would halogenoalkanes have higher boiling points?
Increase Carbon chain length
Halogen further down group 7
How would the mass of a haloalkane compare with the mass of an alkane of the same chain length?
Greater as mass of halogen > mass of H
What is the most important factor in determining halogen reactivity?
The strength of carbon halogen bond
What would bond polarity suggest the order of reactivity would be?
C-F would be most reactive as most polar bond
What would bond enthalpies suggest the order of reactivity would
be?
C-I would be most reactive as lowest bond enthalpy
What is the trend in reactivity of primary, secondary and tertiary haloalkanes?
● The tertiary halide produces a precipitate almost instantly.
● The secondary halide gives a slight precipitate after a few seconds.
● The primary halide takes considerably longer to produce a
precipitate.
Define nucleophile
Electron pair donor
Give 3 examples of nucleophiles
:OH -
:CN -
:NH 3 -
What is nucleophilic substitution?
A reaction where a nucleophile donates a lone pair of electrons to δ+ C atom, δ− atom leaves molecule (replaced by nucleophiles)
What is hydrolysis?
A reaction where water is a reactant
