C14.1 - C14.6 - Using Earths Resources✔️

Question 1

What are finite resoruces?

Answer 1

Resources that are being used up faster than they can be replaced - there is limited amount

Question 2

What are renewables?

Answer 2

Resources that can be replaced a the same rate at which they are used up

Question 3

Why are synthetic products produced?

Answer 3

Chemists provide new synthetic products which supplement or replace natural products - this helps reduce our reliance on natural products

Question 4

Give three examples of renewable resources?

Answer 4

• wood
• leather
• cotton

Question 5

What are synthetic products?

Answer 5

Products which supplement or replace natural products

Question 6

Give each step for sewage treatment?

Answer 6

Water water flows from sewer to treatment plant where it is screened which removes grit and large objects - it then pases through a primary sedimentation tank then through an aeration tank before a final settling tank and into the enviorment

Question 7

What does screening do to sewage?

Answer 7

Removes large solids and grit from the waste water by passing waste through a metal grid

Question 8

What does primary sedimentation tanks do?

Answer 8

Organic waste sinks to the bottom as sludge - remianing water (effluent) taken from the top

Question 9

What does the aeration tank do?

Answer 9

Good bacteria kill harmful bacteria in aeration tanks where is air is pumped through effluent which helps the good/uesefull bacteria as they are normally aerobic

Question 10

What happens to the sludge from sewage?

Answer 10

Removed by the primary sedimentation tank and then digested anaerobicaly by bacteria which releases methane which is used to generate electricity - can also be dried and used as ferteliser on farmland to improve the soil

Question 11

Give two ways copper metal can be obtained from copper ore?

Answer 11

• sulfuric acid is used to produce copper sulfate solution, before extracting the copper metal

-through smelting - copper ore is heated to a high temperature in a furnace with air, to produce impure copper

Question 12

How can we obtain pure copper from impure copper produced through smelting copper ore?

Answer 12

Impure copper is used as the positive electrode in electrolysis cells to make pure copper

Question 13

Issues with obtaining pure copper from smelting and electrolysis? Give 2 reasons?

Answer 13

Requires huge amounts of energy and electricity which is expensive and causes pollution of the enviorment

Question 14

explain in depth how pure copper can be obtained through phytomining?

Answer 14

Plants absorb low-grade copper ions from the soil they are grown in - plants are then burned and the copper is extracted from copper compounds in the ash - the copper ions can be ‘leached’ producing a solution of copper sulfate - displacement by scrap ion and then electorlysis makes pure copper metal

Question 15

Why is the the copper ions ‘leached’ from the ash during phtomining?

Answer 15

Copper ions can be ‘leached’ (dissolved) from the ash by adding sulfuric acid which makes a solution of copper sulfate

Question 16

Explain the process of bioleaching, to produce pure copper?

Answer 16

Bacteria feed on low-grade metal ores by a combination of biological and chemical processes, a solution of copper ions (leachate) can be obtained from waste copper ore - scrap iron and electrolysis is used to extract the copper from the leachate

Question 17

Explain why life cycle assesments are carried out (LCAs)?

Answer 17

Carried out to assess the enviormental impacts of products,processes or services

Question 18

What are the four stages the impacts on the enviorment by products are assessed through LCAs?

Answer 18

• 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.

Question 19

Give the order of the stages in an LCA?

Answer 19

Raw material extraction → manufacture → use/reuse/maintenance → recycle/waste management

Question 20

What is an LCA? issues with them?

Answer 20

Provides an estimate of the total enviormental impacts resulting from all stages in the products life cycle - assigning numerical values to the relative effects of pollutants involves subjective judgement aswell as this they do not take into account differences in the cost or performance

Question 21

What is portable water?

Answer 21

Water that is safe to drink - should have sufficiently low levels of dissolved salts and microbes

Question 22

Example of some of the sterilising agents used for portable water?

Answer 22

• chlorine
• ozone
• ultraviolet light

Question 23

How can fresh water be treated to make is safe to drink?

Answer 23

passing untreated water through filter beds made of sand and gravel to remove solid particles and adding chlorine or ozone to sterelise the water by killing microrganisms or by using ultraviolet light

Question 24

How can countries that do not have access to large volumes of fresh water obtain the needed water?

Answer 24

Through desalination of salty water or sea water which is done by distilation or by processes that use membranes such as reverse osmosis - these process require large amounts of energy

Question 25

Explain how glass bottles for example can be reused?

Answer 25

Glass bottles can be crushed and melted to make different glass products

Question 26

How can meltals be recycled?

Answer 26

By melting them and recasting or reforming into different products

Question 27

Name two products which could be reused?

Answer 27

• glass bottles
• plastic carrier bags