Haloalkanes Flashcards
(20 cards)
What is a haloalkane?
An alkane with a halogen attached
How to make a haloalkane with an alkane?
Free radical substitution
How to make a haloalkane with an alkene?
Nucleophilic substitution
How to make a haloalkane with an alcohol?
Electrophilic addition
What is the general formula for a haloalkane?
CnH2n+1X
X is a halogen
Which haloalkane is the most reactive when considering only bond enthalpy?
Iodine is the most, then bromine then chlorine
Which haloalkane is the most reactive when considering only polarity?
Chlorine is the most, then bromine then iodine
What happens when a chloroalkane alkane mixes with ethanol and AgNO3?
A white precipitate
What happens when a bromoalkane alkane mixes with ethanol and AgNO3?
A cream precipitate
What happens when a iodoalkane alkane mixes with ethanol and AgNO3?
A yellow precipitate
What does CFC stand for?
Chlorofluorocarbons
What were CFC’s used for?
Fridges
Cleaning equipment
Aerosol
Fire extinguishers
Why were CFC’s used?
It has high bond energies in the C-Cl and C-F
It is very unreactive gas
What is an example of CFC’s?
CF2Cl2CF2Cl2
CF2Cl2
What happens to CFC’s in the ozone?
The CFC goes through homolytic fission from the UV light to make a chlorine radical - initiation
The chlorine radical can react with the ozone to make oxygen and a ClO radical
The ClO can react with ozone to make oxygen and a chlorine radical
What is the reaction equations with CFC’s in the ozone?
Initiation:
UV .
CF2Cl2 —> CClF2 + Cl
Propagation: . . Cl + O3 —> ClO + O2 . . ClO + O3 —> Cl + 2O2
What are the negative affects of CFC’s?
They cause: Increased risk of sunburn Increased risk of cataracts Increased risk of cancer Accelerated skin ageing
What agreement caused the CFC’s to be banned?
The Montreal Protocol
What are the changes that the Montreal Protocol made?
CHC’s were banned
Aerosols now use butane
Old fridges must be recycled ins special way
Where are CHC’s still used?
Low income use them because of their cheapness and many uses
