Halogenoalkanes and the environment

Question 1

Name some polymers containing halogens which are manufactured.

Answer 1

Poly(vinylchloride) (PVC) and poly(tetrafluoroethene)

Question 2

Describe why Teflon (PTFE) is so ggod for non-stick frying pans?

Answer 2

Carbon-fluorine bonds are very strong, which makes PTFE inert and resistant to chemical attack. This chemical inertness, along with its heat resistance, electrical insulating properties and non-stick qualities.

Question 3

Give some examples of were PVC is used.

Answer 3

PVC is used in many varied applications such as drainpipes, plastic window frames, sports equipment, children’s toys and packaging.

Question 4

What are CFC’s?

Answer 4

Chlorofluorocarbons

Question 5

Were does the stability of CFC’s come from?

Answer 5

From the strength of the carbon-halogen bonds within their structures.

Question 6

What are the problems with CFC’s?

Answer 6

CFC’s remain stable until they reach the stratosphere, where they break down in the presence of ultraviolet radiation to form chlorine radicals. These chlorine radicals are thought to catalyse the breakdown of the ozone layer. Ozone absorbs much UV radiation, with the ozone depleting it reaches people and gives them cancer.

Question 7

What were CFC’s originally developed for?

Answer 7

CFC’s were developed as refrigerants, propellants, blowing agents and solvents.

Question 8

Name some replacements for CFC’s.

Answer 8

Hydrofluoralkanes, HFCs and hydrofluorohydrocarbons are alernatives. They are the same as CFC’s but they only do 1/10 of the damage to the atmosphere CFC’s would do.