Halogenoalkanes Flashcards
what type of bond do halogenoalkanes contain
C-X bond is a polar bonds
as halogens are much more electronegative than carbon
what nucleophiles do halogenoalkanes undergo substitution with and how many steps do they do
OH - = one step
CN- = one step
NH3 = two steps
what will be d+ and what will be d- in nucleophilic substitution
the C in C-X will be highly attractive to nucleophiles as it will be d+ and the X will be d-
what does the nucleophilic substitution look like between chloroethane and ammonia
what is the ozone
a naturally formed layer in the upper atmosphere
why is the ozone beneficial
it absorbs ultraviolet radiation
how is chlorine formed in the upper atmosphere
when uv radiation causes c-cl bonds in CFCs to break into free radical chlorine atoms
what do chlorine atoms do in the ozone
catalyse the decomposition of ozone and contribute to the hole in the ozone layer
what have CFCs done to ozone layer
created holes in the ozone
what do we do now since finding out what CFCs do
use alternatives that are chlorine free such as HFCs
what are the 3 stages of how the ozone is depleted
- initiation
- propagation
- termination
how does the intitation of cl free radicalisation look
CFCl3 -> Cl* + *CFCL2
what is the propagation stage of free radicalisation
1- Cl* + O3 -> ClO* + O2
2- ClO* + O3 -> Cl* + 2O2
what is the termination stage of free radicalisation
ClO* + ClO* -> Cl2O2
what is special about cl*
it is regenerated so can react with more compounds in the atmosphere
