Unit 2.3 The impact of chemistry

Question 1

What’s the main thing of this topic?

Answer 1

Sustainability, efficiency, effectiveness, biodegradable
In addition,
Non-renewability, waste products, global warming, excessive dependence

Ya name them

Question 2

U know what, I may copy word for word. For sure at the end, I’ll break it down, riggghhhtt?

Answer 2

<_<

Question 3

Considering the impact of chemistry?

Answer 3

Our lifestyles demand goods and services, these are our social requirements. Being able to produce things cheaply is economic considerations. However, we need to consider environmental issues which may have social and economic consequences (inconvenient or costly)

• World resources are running out and are non-renewable
• We need to reduce the waste of valuable resources
• Reduces the expense of disposal
• Reduces the expense of making things from raw materials
• Avoids environmental problems posed by waste:
  1. Landfill
  2. Greenhouses gases
  3. Acid rain
  4. Pollution
  5. Destroying habitats
  6. De-forestation leading to climate change and destruction of ecosystems

Question 4

Basics[?] of considering the impact of chemistry?

Answer 4

• Better way to prevent waste than to treat it afterwards
• Aim for maximum atom economy
• Use processes which require fewer chemicals
• Unsure chemicals, methods and solvents are as safe as possible:
  1. Avoid any that are toxic or dangerous to human health
  2. Avoid any that are harmful to the environment
  3. Avoid accidents
  4. Design for biodegradation
• Reduce the energy requirements of processes
• Use alternative or renewable energy resources
• Use renewable raw materials, not finite resources
• Use catalysts where possible
• Waste products should be designed to be biodegradable
• Reduce the risk of explosions and fires

Question 5

When looking at products (and reactants) what implications must u consider of their use?

Answer 5

• Is this the most efficient process?
  Is there a better reaction we could use that wastes less?
• Where should the industry be sited?
  Consider social, economic and environmental issues
• Are the by-products, products and reactants safe?
  Can we use anything less toxic or explosive?
• Is the process environmentally damaging?
  Does it cause pollution or destroy habitats?

Question 6

Which chemical industry, what do they mainly require?

Answer 6

• Transport links
• Good source of trained labour
• Access to raw materials and power

Question 7

For chemical engineers running industrial processes, what 2 extremely important tasks that must be undertaken?

Answer 7

• A mass balance
• An energy balance

Question 8

Explain a Mass balance?

Answer 8

• Involves accounting for total mass of reactants and total mass of products
• Including waste products and emissions
• Unit 1.3 principles & equations = important
• For unfamiliar processes all relevant data will be given

Question 9

How to find % yield?

Answer 9

(What u actual get/what u theoretically get) x 100
or
(mass of product obtained/maximum theoretic yield) x 100

Question 10

How to find atom economy?

Answer 10

(mass of required product/total mass of reactants) x 100

I mean, mass or mr, same thing

Question 11

Explain an Energy balance?

Answer 11

• Involves accounting for total input of energy and total output of energy
• Including waste energy given out to environment
• Students should appreciate the role of water as a cooling medium to remove heat evolved in the process

Question 12

What are the 2 factors to consider for the development of a chemical process?

Answer 12

• Social implications
• Economic factors

Question 13

Explain social implications?

Answer 13

Includes:
- Availability of labour
- Impact on local amenities
- Use of land (brown field v green field sites)

Question 14

Explain economic factors?

Answer 14

Oh boy… I’m writing everything.

Siting the plant:
Depending upon the scale of operation, choices have to be made and these will be commercial decisions. Local Authority planning permission must be granted for any new development. There may be financial incentives to set up in some areas. Transport considerations are important. Many new plants are set up in or around existing concentrations of industry since there are relatively few companies that have sufficient wealth to start a new venture. Where existing concentrations of industry exist, there are likely to be existing transport and communication links, a working population to employ and availability of services such as energy and water

Question 15

Why do we need energy?

Answer 15

Hmm, very tangible answer….

Question 16

State some non-renewable sources

Answer 16

• Oil
• Natural gas
• Coal
• Nuclear energy

Question 17

State some renewable sources?

Answer 17

• Wind power
• Solar power
• Bioenergy (organic matter burned as fuel)
• Hydroelectric (including tidal energy)

Question 18

Benefit of improving efficiency?

Answer 18

• Reduce energy requirements
  Research into car engines is fairly successful, it leads to reduction in costs. This has the advantage of being popular with customers who save money on fuel costs

Question 19

Describe hydrogen as a fuel source?

Answer 19

• Advantage of being renewable
• Can obtain from [water?/wind, solar, geothermal, or biomass?]
• Doesn’t produce pollution
• Waste product is water

Disadvantages are that hydrogen is not naturally occurring (on Earth) and energy is needed to produce it

Question 20

What is carbon neutral?

Answer 20

A chemical process such as fuel combustion does not lead to an overall increase in CO₂ levels. Although combustion does generate CO₂, this is offset by the fact that the fuel, such as biomass or sugar cane, has absorbed the same amount of CO<sub”</sub> i being made by photosynthesis

Uhhh…. isn’t there a simpler way?

Question 21

Why is carbon neutrality important?

Answer 21

Benefits to communities and society as a whole. They include:
- Less environmental pollution
- Improvements to health
- A boost to sustainable economic growth and the creation of green jobs

Question 22

What is biomass?

Answer 22

Carbon neutral
Leaves a zero carbon foot-print

Question 23

What are the processes that mean biomass is not carbon neutral?

Answer 23

Needs to be harvested, transported and buildings need to be built to burn it in- all these require carbon

Question 24

Describe renewable energy

Answer 24

Sources produced by physical processes are theoretically, non-polluting, however turbines, generators and transport of electricity all require forms of construction and therefore require energy

Many are very inefficient. No need to look at these processes as they are interested in chemical processes

Question 25

Describe nuclear power

Answer 25

Radioactive fission of uranium converts mass (around 1%) into energy. Around 20% of our countries energy could be produced this way

Question 26

Problems with nuclear power?

Answer 26

• Massive costs to build and decommission power plants
• Extremely dangerous consequences of radiation leaks
• Difficulty of storing the highly radioactive waste safely

Question 27

What would be a much safer nuclear power method?

Answer 27

Nuclear fission of hydrogen into helium (as in the sun):
- Theoretically more safer (no radioactive reactants/products)
- More efficient process

To date unfortunately, this process cannot be achieved technically

Question 28

Describe solar power

Answer 28

Solar power panels can directly heat water. However, to produce electricity semiconductor panels (using silicon or gallium arsenide) are now often over 10% efficient and becoming more popular. Power outputs of 0.5kWm^-1 are being achieved

• Just increased efficiency and usage

Question 29

How does a catalyst reduce the temperature needed for a successful reaction?

Answer 29

Provides an alternate route with a lower activation energy

Question 30

Define VOCs

Answer 30

Volatile organic compounds: bad for the environment

e.g. Diesel engines
Give off nitrogen oxides which cause acid rain. Addition of ammonia converts these into harmless nitrogen

Question 31

Major disposal problem of widespread use of addition polymers?

Answer 31

• Bonds within polymers are strong, covalent and non-polar
• Makes most polymers resistant to chemical attack
• Non-biodegradable as it can’t be broken down by bacteria
• Causes problems trying to dispose
  e.g. Plastic waste buried in landfill sites
  They remain unchanged for decades ∴ current landfill sites fill very rapidly with the quantities of plastic material we throw away

Question 32

What are the alternative methods of dealing with polymer waste other than landfill?

Answer 32

1. Recycling
2. Polymers as a fuel source
3. Feedstock recycling
4. Biodegradable and compostable polymers

Question 33

Explain recycling

Answer 33

• Simple and cheap
• By reusing polymer without processing
• However only possible in very few cases

More common to have to process the polymers by first sorting them and then reclamation

Sorting is a difficult process…

Question 34

Explain polymers as a fuel source

Answer 34

• Burning polymer waste as a method of generating electricity
• Problem: certain polymers e.g. PVC can release toxic fumes when burnt
• Incinerators must be equipped of ways of dealing with harmful emissions

Question 35

Explain feedstock recycling

Answer 35

• Polymers cracked into chemicals
• Used to produce new polymers or other organic chemicals
• Some chemicals produced during cracking may be used as fuel

All these methods are ways in which we are reducing the amount of crude oil…

Question 36

Explain biodegradable and compostable polymers

Answer 36

• Lots of research done
• Into producing polymers from renewable raw materials
• Where monomers come from plants and animals
• These new polymers degrade much more quickly in landfill sites

Question 37

Honestly the rest, look in booklet. This just kinda stupid to have this many cards and learning all these. And it’s not even any calculation this a whole history lesson

Answer 37

…