Chloroalkanes Flashcards
What are chloroalkanes?
Alkanes with one or more hydrogen atoms substituted by a chlorine atom
What is the name of the reaction in which halogens and alkanes react?
Photochemical reaction
What is a free radical substitution?
When a hydrogen atom is substituted by a chlorine or bromine
What starts off a photochemical reaction?
UV light
What is a free radical?
A particle with an unpaired electron
How are free radicals formed?
When a covalent bond splits evenly, giving one electron to each species
Are free radicals reactive or unreactive?
Reactive
What are the three steps of free radical substitution?
Initiation
Propagation
Termination
Why is UV light used in the reactions?
It has enough energy to break the bonds
What is initiation?
The production of free radicals
What is the equation for initiation which forms chlorine free radicals?
Cl2 –-U.V–> 2Cl∙
What happens in propagation?
The free radicals are used up and created in a chain reaction
What happens if the chlorine is in excess?
The hydrogen atoms on methane will eventually be replaced by chlorine atoms
What are the three products you will get from substitutions of excess chlorine in methane?
Dichloromethane
Trichloromethane
Tetrachloromethane
What is termination?
Two free radicals joining together to form a stable molecule
Terminates the chain reaction
