halogens and CFC's (1 Viewer)

[nippy]

hi
can someone plz be kind enough to tell me the precise difference between halogen’s and CFC’s……… all the text’s seem to have a confusing and some what contradicting explanation. I know they r both haloalkanes.

need hepl quick

 

[Xayma]

Halogens are Group VII elements.

Haloalkanes are alkanes where a H atom has been replaced by a Halogen.

CFC's are where a molecule only has carbon, flourine and chlorine atoms.

 

[nippy]

halons

so how do halons fit into all of this i mean in relation to CFC's . how r they different.

 

[Xayma]

Halon's are Haloalkanes that contain Bromine. They are not CFC's.

 

[CM_Tutor]

I think the definition is narrower. CFCs contain only C, F and Cl and no H. Halons (as Xayma has said) contain bromine, but I would not consider CH₃Br, for example, a halon. To be a halon the compound should have C, Br and other halogens, and no H. For example, the old yellow BCF fire extinguishers contained a halon bromochlorodifluoromethane, CBrClF₂. They are relevant to the syllabus as halons do even more damage to the ozone layer than do CFCs, because the bromine free radical is a better catalyst for ozoone destruction than is the chlorine free radical.

 

[tinky]

CFCs contain only C, F and Cl and no H. .

but I iodine is also included right.......

 

[Xayma]

For a CFC no, CFC's contain no other atoms bar C, F and Cl. If it was to contain "I" it would be a haloalkane.

 

[CM_Tutor]

No, Xayma is correct - CFCs are C, F and Cl ONLY.

Inclusion of iodine might be possible in a halon, or in an FIC - fluoroiodocarbon, such as CF₂I₂. (FICs are another class that has been developed as potential CFC alternatives.) Or, as Xayma suggests, it would probably be a haloalkane.