Combined Chemistry - 5.10 Flashcards Preview

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Flashcards in Combined Chemistry - 5.10 Deck (25)
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1
Q

Suggest two ways in which Humans use the Earth’s resources.

A

Any two from:

warmth

shelter

food

transport

2
Q

What is meant by the term ‘sustainable development’?

A

Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs.

3
Q

Give one example of a natural product that has been supplemented by, or replaced by, agricultural or synthetic products.

A

Suggestions include:

  • Man made polymers have replaced natural rubber in a number of uses (e.g. car tyres)
  • Concrete has replaced natural stone in some buildings
  • Manure replaced by artificial fertilisers
4
Q

What is potable water?

A

Water that is safe to drink.

5
Q

Is potable water pure water?

A

No, because it contains dissolved substances

6
Q

What two things must drinking water have low levels of?

A
  • Dissolved salts
  • Microbes
7
Q

Describe how potable water is produced in the UK.

A
  • Choose an appropriate source of fresh water
  • Passing the water through the filter beds
  • Sterilising the water
8
Q

Name the three different sterilising agents that can be used to make potable water.

A
  • Chlorine
  • Ozone
  • Ultraviolet light
9
Q

Name two processes that can be used to desalinate water.

A
  • Distillation
  • Reverse Osmosis
10
Q

Name the process by which salt is removed from water.

A

Desalination

11
Q

Why does industrial waste water need treatment before being released into the environment?

A

To remove organic matter and harmful chemicals

12
Q

Why does sewage and agricultural waste water need treatment before being released into the environment?

A

To remove organic matter and harmful microbes

13
Q

Describe the four main stages in the process of sewage treatment

A
  • Screening and grit removal
  • Sedimentation to produce sewage sludge and effluent
  • Anaerobic digestion of sewage sludge
  • Aerobic biological treatment of effluent
14
Q

Higher Q. Why are new ways of extracting copper from low-grade ores needed?

A

High grade copper ores are running out.

15
Q

Higher Q. What big advantage do phytomining and bioleaching have over traditional copper mining methods?

A

These methods do not involve digging, moving and disposing of large amounts of rock.

16
Q

Higher Q. Describe the main stages in the phytomining process.

A
  • Plants are grown on low-grade copper ores
  • Plants absorb copper compounds
  • Plants are harvested then burned
  • Ash contains metal compounds

*Then electrolysis or displacement may be used to remove copper from the ash.

17
Q

Higher Q. How does bioleaching work?

A

Bacteria produce leachate solutions that contain metal compounds

*Then electrolysis or displacement may be used to remove copper from the ash.

18
Q

Higher Q. What two methods can be used to extract the copper from copper compounds after phytomining and bioleaching?

A
  • Electrolysis
  • Displacement using scrap iron
19
Q

What are the four stages of a product’s life that are assessed by Life Cycle Assessments (LCAs)?

A
  • Extracting and processing raw materials
  • Manufacturing and packaging
  • Use and operation during its lifetime
  • Disposal at the end of its useful life (including transport and distribution at each stage)
20
Q

What effects are difficult to predict by Life Cycle Assessments (LCAs), making them a little subjective?

A

Pollutant effects

21
Q

Name three materials that are produced from limited raw materials.

A

Any three from:

metals, glass, building materials, clay ceramics, plastics

22
Q

What are the four main advantages of reusing and recycling materials?

A
  • Conserving limited resources
  • Conserving energy
  • Reducing waste (e.g. in landfill)
  • Reducing environmental impacts
23
Q

How are glass bottles recycled?

A

They are crushed and melted to make different glass products.

24
Q

How are metals recycled?

A

They are melted and recasted or reformed into different products.

25
Q

Why is scrap steel added to iron from a blast furnace?

A

To reduce the amount of iron that needs to be extracted from iron ore.