Haloalkanes Flashcards
Are haloalkanes soluble in water?
they are slightly soluble as C-H bonds are non-polar, Although the C-X bond is polar it isn’t polar enough for the whole molecule to dissolve well in a polar solvent
Why do Haloalkanes have a polar bond
Halogen has a higher electron negativity then carbon, this electronegative difference produces permanent polarisation hence a permanent dipole is formed
Which intermolecular forces do Haloalkanes have?
Permanent Dipole-Dipole and VDW
C-X Bond polarity makes a permanent dipole
How would the mass of a haloalkane compare with the mass of an alkane of similar chain length
Greater mass as the only discrepancy is that haloalkanes have a halogen substituted in for a hydrogen molecule
Halogen mass > Hydrogen mass
What is the most import factor i’m determining a haloalkanes reactivity
Carbon-Halogen bond enthalpy
Lower it is the more reactive the molecule
Higher atomic radius = lower enthalpy
What is a Nucleophile
An electron pair donor
A negatively charged ion or molecule with a a lone pair of electrons which can be donated to an electron deficient atom
Explain Nucleophilic Substitution
1) nucleophile donates lone pair of electrons to delta positive carbon,
2) atom with the highest tendency to leave, leaves the molecule
Draw the mechanism for the reaction of bromoethane with NaOH (aq)
Draw the mechanism for the reaction of bromoethane with NH3
Draw the mechanism for the reaction of bromoethane with NaOH in ethanolic
What are CFC’s
What is the problem associated with them?
What are they being replaced with?
Chlorine-fluoro-carbons haloalkanes containing Carbo. Flourine and chlorine only (no hydrogen)
Unreactive in normal conditions, however in the presence of uv light they catalyse the breakdown down of ozone to oxygen in the atmosphere via free radical substitution
What are the reactants and conditions for the elimination reaction of haloalkanes
what is formed
Hot and ethanoic
NaOH or KOH dissolved in ethanol
alkene , water and a halogen ion
