Haloalkanes Flashcards
What is a nucleophile
an electron pair donor ( with lone pair )
What causes reactivity in haloalkanes
polarity of C-X bond
Electronegativity of the halogens causes partial charges
What are carbons attracted too
nucleophiles
what mechanism occurs in a haloalkane that reacts with a species with a lone pair
nucleophilic substitution
What type of haloalkane reacts faster with a nucleophile
tertiary
Why does a C-I bond react faster with nucleophiles than other halogens
lower electronegativity
what is an organohalogen
molecules that contain at least 1 carbon-halogen bond
What are organohalogens used for
solvents, refrigerants, pesticides
Can you find organohalogens in nature
no
How much of the ozone layer is made of ozone
tiny fraction
what is the role of ozone in the ozone layer
to prevent UV light reaching the earth’s surface
What can UV light cause
sun burns, genetic disease, small risk of cancer
How can Oxygen form ozone
O2 —–> 2O (With UV light)
O2 + 0 O3 (reversible reaction)
What are CFCs
They are made of carbon, fluorine and chlorine where they have highly strong C-X bonds that are very stable
What effect do CFCs have on the earths atmosphere
breaks down into chlorine radicals which can affect ozone production
How do CFCs break into chlorine radicals
UV light breaks the bonds
What is the initiation step of the break down of ozone from CFCs
CF2Cl2 —-> CF2Cl* + Cl* (UV Light breaks this bond)
What are the propagation steps of the break down of ozone from CFCs
Cl* + O3 —-> ClO* + O2
ClO* + O —-> Cl* + O2
How do termination steps occur
when 2 radicals collide causing the whole cycle of propagation steps to end
What happens if NO* forms and reacts with ozone
lightning strikes can occur
What are the propagation steps of NO* breaking down ozone
NO* + O3 —–> NO2* + 02
NO2* + 0 —> NO* + 02
Name 3 nucleophiles
:OH- ions
H2O: molecules
:NH3 molecules
