Green chemistry

Question 1

What does sustainability mean?

Answer 1

Sustainability means the development of processes that prevent the depletion of natural resources.

Question 2

Give all the philosophies of green chemistry.

Answer 2

1) Using renewable sources - using solar energy not fossil fuels.
2) Saving money - Using fewer chemicals or less energy.
3) Preventing waste - So time and money is not spend on cleaning up later.
4) Maximising atom economy - Making only what you need.
5) Recycling/biodegradability - Materials should be harmless at the end of their life.

Question 3

Explain how and why carbon dioxide is used in foam.

Answer 3

• CFC’s were once used as the blowing agents but with the environmental issues with it carbon dioxide has replaced it.
• Waste carbon dioxide from industrial and natural sources are used, ensuring that there is not net increase in global carbon dioxide.

Question 4

Explain how carbon dioxide is used as a solvent.

Answer 4

• By altering pressure and temperature carbon dioxide can be converted into an unusual state called a supercritical fluid. The resulting solvent is known as supercritical fluid.
• This means that scCO2 can be used as a solvent with materials that would decompose at high temperatures.

Question 5

Explain how CO2 is used for beer.

Answer 5

CO2 produces a natural fizz in beer.