Haloalkanes Flashcards
What is the ozone layer?
A high concentration of ozone molecules in a layer of the stratosphere about 15-30km above the Earth’s surface
What is the chemical formula for ozone?
O3
What does ozone absorb?
UV radiation for the sun
What does CFCs stand for?
Chlorofluorocarbons
What are CFCs?
A class of organic compounds that contain chlorine and fluorine atoms
What were CFCs used for?
Refrigerators
Aerosols
Fire-safety equipment
What are the example of CFCs?
Dichloro-difluoro-methane
1,1,1-trichloro-2,2,2-trifluoro-ethane
What are the properties of CFCs?
Inert
Non-toxic
What does it mean if they are inert?
They are stable so won’t react with other substances
What does being stable allow CFCs to do?
Allows them to exist in the atmosphere long enough to reach stratosphere
What does the UV radiation do?
Break the C-Cl covalent bond to form free radicals
What are the stages for CFC zone depletion?
Initiation: CF2Cl2 —-> CF2Cl + .Cl
Propagation 1: .Cl + O3 —-> .ClO + O
Propagation 2: .ClO + O —-> .Cl +O2
What is the overall equation for ozone depletion?
O3 + .O —-> 2O2
What does hydrolysis of a haloalkane involve?
Haloalkane + hydroxide —-> Alcohol + halogen
What is the process of hydrolysis of haloalkane called?
Nucelophillic substitution
What are the factors that effect rate of hydrolysis for haloalkanes?
Shielding
nuclear charge
Atomic radius
What happens hydrolysis rate of reaction down the group for haloalkanes?
It increases
Why does the hydrolysis rate for haloalkanes increase down the group?
Because the C-I is the weakest bond since it the biggest atomic radius so it has the most shielding so it has the weakest nuclear attraction
What is the test for the rate of reaction for haloalkanes?
Add ethanol ans silver nitrate to the haloalkane
Time how long the precipitate takes to form
What is the ionic equation for the test for rate of reaction of haloalkanes?
Ag+ (aq) + Cl- (aq) —-> AgCl(s)
