13 - Halogenoalkanes Flashcards
What intermolecular forces do haloalkanes form?
Dipole-dipole
Van der Waals
Give 3 uses of halogenoalkanes.
Solvent
Pharmaceuticals
Refrigerants
Describe the solubility of halogenoalkanes.
Not soluble in water as bonds aren’t polar enough
Mix with hydrocarbons
How does branching affect boiling points of halogenoalkanes?
More branching decreases boiling point.
Compare the boiling points of alkanes with halogenoalkanes.
Alkanes have lower boiling points, as they are less polar and have lower relative molecular masses.
What is the most important factor in determining the reactivity of halogenolalkanes.
Bond enthalpy
Why is a haloalkane with a Cl less reactive than a Br?
C-Cl is a stronger bond than C-Br.
Define the term nucleophile. (1)
Electron pair donor
Define substitution, in reference to nucleophilic. (1)
Replacement of halogen atom by nucleophile.
Define bond enthalpy. (1)
Enthalpy required to break bond.
Define hydrolysis. (1)
Splitting molecules using water.
Give three conditions of elimination reactions.
Hot
Ethanol as solvent
Concentrated reactant
State the role of a hydroxide ion in elimination reactions.
Base
What characteristic allows haloalkanes to undergo nucleophilic substitution?
Polar C-X bond
Why is ozone positive?
Absorbs ultraviolet radiation
Why do CFCs affecting ozone depletion?
UV light causes C-Cl bonds in CFCs to break
Chlorine atoms cause ozone decomposition
Give the chemical formula for ozone.
O3
What does NH3 attack when N+ H?
H
How does CFC cause global warming?
Polar bonds
Absorbs infrared radiation
Describe the decompositon of ozone using radical equations?
- Cl + O3 –> ClO * + O2
ClO * + O3 –> 2O2 + Cl *
