Origins of halons and CFCs (2 Viewers)

[P.I.M.P.]

u need to know haloalkanes:

Syllabus:
-identify the origions of CFC's and halons in the atmosphere
-identify and name examples (of isomers excluding geometrical and optical) of haloalkanes up to 8 carbon atoms

 

[+:: $i[Q]u3 ::+]

Originally posted by loser
So the only source of halons is fire extinguishers?

well.. halons have been banned for a while.. u ever seen a yellow fire extinguisher? =P but i guess the syllabus is asking for it =P

 

[mercury]

yep... sique's completely right, they js want u know that halons were widely used in those yellow fire extinguishers before but now u shouldn't see any of them around coz they are BANNED.

 

[AK Gumbi]

wots the difference in halons and haloalkanes?

 

[mercury]

Halons are bromofluorocarbons used to extinguish fires in electrical and computer systems. Examples include, bromochlorodifluoromethane and bromotrifluoromethane. All yellow fire extinguishers containing halons in Australia should have been withdrawn from use by now.
Halons were produced in much smaller amounts than CFCs but the C-Br bond is weaker than the C-Cl and therefore more easily broken. More importantly on a per atom basis, Br is 10-100 times as destructive of ozone as Cl.
The 1987 Montreal Protocol applies to halons as well as CFCs. The protocol was amended in Copenhagen in 1992 to state that production of CFCs, halons and the solvent CCl4 (carbon tetrachloride) was to cease entirely by 1996.

 

[mercury]

Haloalkanes are just relatives of alkanes, containing one or more halogen atoms (ie. F, Cl, Br, I). ie. haloalkanes contain H, C and halogen(s).