C14 - The Earth's Resources

Question 1

Where do natural resources come from ?

Answer 1

Earth, sea and air

Question 2

What can natural products be replaced by ? And give some examples

Answer 2

Some natural products can be replaced synthetic products or improved upon by man-made processes.

For example, rubber is a natural product that can be extracted from the sap of a tree however man-made polymers have now been made which can replace rubber in uses such as tyres

Synthetic products make it so that the natural products last longer as you would be using synthetic instead of natural

Question 3

What does agriculture provide conditions for ?

Answer 3

Agriculture provides conditions where natural resources can be enhanced for our needs

Question 4

What are finite resources ?

Answer 4

They are resources that are used up faster than they can be replaced

Question 5

Renewable resource def

Answer 5

A renewable resources reform at a similar rate to or faster than we use them

Question 6

What are 3 examples of finite resources ?

Answer 6

Metals, plastics and fossil fuels

Question 7

Give 3 examples of renewable resources ?

Answer 7

Timber, cotton, rubber

Question 8

What are 3 examples of synthetic products ?

Answer 8

Polyesters, PVC, nylon

Question 9

How to purify water practical (RP)
Explain how to do it

Answer 9

1. Use the universal indicator paper to measure the pH of the water sample.
2. Accurately weigh an empty evaporating basin and record to two decimal places.
3. Pour 10 cm° of water sample 1 into the evaporating basin.
4. Heat the evaporating basin on a tripod and gauze using a Bunsen burner until the solids star to form and the majority of water has evaporated
5. Weigh the cooled evaporating basin again and calculate the mass of the solids that were dissolved in the water.
6. Record your results in a table:

Question 10

What is potable water ?

Answer 10

Potable water is water that’s been treated or is naturally safe for humans to drink - it’s essential for life.

Question 11

Is potable water pure ?

Answer 11

Chemists wouldnt call it pure. Pure water only contains H2O molecules whereas potable water can contain lots of other dissolved substances

Question 12

What type of water is rain water

Answer 12

Rain water is a type of fresh water

Question 13

How can you treat fresh water sources ?

Answer 13

Filtration - a wire mesh screens out large twigs etc, and then gravel and sand beds filter out any other solid bits

Sterilisation - the water is sterilised to kill any harmful bacteria or microbes. This can be done by bubbling chlorine gas through it or by using ozone or ultraviolet light

Question 14

What is desalination ?

Answer 14

Getting rid of the salt

Question 15

How do you make sea water fit to drink ? Desalination

Answer 15

Throught distillation -

Question 16

What’s a life cycle assessment ?

Answer 16

A LCA looks at every stage of a products life to assess the impact it would have on the environment

Question 17

What are the 4 stages of LCA and explain them ?

Answer 17

Getting raw materials:
-extracting raw materials needed for a product can damage the local environment, e.g. mining metals
-raw materials oftwn need to be processed to extract the desired materials and this often needs large amounts of energy

Manufacturing and Packaging:
- Manufacturing products and their packaging can use a lot of energy resources and can also cause a lot of pollution, e.g. harmful fumes such as carbon monoxide or hydrogen chloride.

• You also need to think about any waste products and how to dispose of them. The chemical reactions used to make compounds from their raw materials can produce waste products. Some waste can be turned into other useful chemicals, reducing the amount that ends up polluting the environment.

Using the product:
1) The use of a product can damage the environment.
For example, burning fuels releases greenhouse gases and other harmful substances. Fertilisers can leach into streams and rivers causing damage to ecosystems.

2) How long a product is used for or how many uses it gets is also a factor - products that need lots of energy to produce but are used for ages mean less waste in the long run.

Product Disposal:
1) Products are often disposed of in landfill sites.
This takes up space and pollutes land and water, e.g. if paint washes off a product and gets into rivers.

2) Energy is used to transport waste to landfill, which causes pollutants to be released into the atmosphere.

3) Products might be incinerated (burnt), which causes air pollution.

Question 18

Compare the life cycle assessments for plastic and paper bags

Answer 18

Raw materials for plastic bag - crude oil
Raw material for paper bag - timber

Manufacturing and packaging for plastic bag - the compounds needed to make the plastic are extracted from crude oil by fractional distillation, followed by cracking and then polymerisation. Require energy but minimal waste
Manu and packaging for paper bag - pulped timber is processed using lots of energy. Lots of waste made

Using the product plastic bag - Can be reused. Can be used for other things as well as shopping, for example bin liners
Using the product plastic bag - usually only used once

Product disposal - Recyclable but not biodegradable and will take up in landfill and pollute land
Product disposal - Biogradable, non-toxic and can be recycled

Question 19

What is sustainable development ?

Answer 19

It is an approach to development that takes account of the needs of present society while not damaging the lives of future generations

It requires that we reduce resource use

Question 20

Why are chemists important for sustainable development ?

Answer 20

Chemists develop new products and processes that use
less resources e.g. chemists have developed catalysts that reduce the amount of energy needed for reactions in industry.

Question 21

What are the 3 Rs and what do they do ?

Answer 21

Reduce , reuse and recycle

Helps reduce the demand for limited resources
They help reduce the amount of waste produced

Question 22

Copper is a finite resource. One way to improve its sustainability is by extracting it feom low grade ores (ores without much copper in). What are the ways of doing this ?