Using Resources Flashcards
What is sustainable development?
Meeting our needs today without compromising the ability of people in the future to meet their needs.
What are finite resources?
Resources which are not being replaced as quickly as they are being used so will run out.
What are renewable resources?
They are resources that are being made quickly enough to be replaced as we use then.
What artificial materials can replace material for clothing?
Cotton and wool can be replaced by artificial polymers such as nylon.
What artificial material can construction materials for buildings be replaced with?
Wood from trees can be replaced by bricks and steel.
What is an example of a natural food that can be replaced by manufactured food?
Meat from animals can be replaced by mycoprotein from fungi grown in fermenters.
What is potable water?
Water that is safe to drink, it contains dissolved substances including mineral ions and gases.
How is water sterilised?
- Fresh water is filtered
- Then chlorine or ozone is bubbled through the water to sterilise it / ultraviolet light is used
Why is fresh water treated using filtration and sterilisation?
Filtration removes insoluble particles and sterilisation kills harmful microbes.
What is desalination?
Removing salts from water that would make it unsafe to drink. It can be carried out using simple distillation or reverse osmosis.
Explain how reverse osmosis works.
Water is forced through a partially permeable membrane. This membrane lets water molecules through but not larger molecules, ions, bacteria, viruses or insoluble particles.
Why is desalination only used if fresh water supplies are limited?
Desalination and reverse osmosis need a lot of energy.
Describe how to analyse water samples.
- Measure and record the mass of sn empty evaporating basin
- Add a known volume of a water sample
- Place the evaporating basin and it’s sample on a tripod and gauze
- Heat from below using a Bunsen burner
- Stop heating just before all the water has evaporated
- Allow to cool, then measure and record the mass of the basin
This shows the mass of dissolved solids in each sample.
Describe purifying a water sample.
Simple distillation to obtain pure water.
Why might a sample not have a pH of 7?
It could contain dissolved substances which dissolve to form acidic or alkaline solutions.
Why might a thermometer not show 100 degrees Celsius in boiling distilled water?
The thermometer may not be calibrated properly.
What is anaerobic digestion?
Breaking down substances in the absence of air and oxygen.
What is aerobic biological treatment?
Treatment that uses living things such as bacteria in the presence of air or oxygen.
Why is it easier to obtain potable water from fresh water rather than from waste water?
Many more stages are needed to test waste water to make it safe to drink.
What is the process of phytomining?
- Plants grow on soil with low concentrations of copper compounds
- Plants absorb copper ions and concentrate them in their cells
- Plants are harvested and then burned
- Ash from burned plants has high concentrations of copper compounds so is processed to produce copper metal
What is bioleaching?
Some bacteria can absorb copper compounds and obtain energy from them through chemical reactions. These bacteria produce a solution called leachate which has copper compounds in high enough concentrations to make processing worthwhile.
How can copper solutions be processed to extract copper?
Electrolysis or displacement reactions using scrap iron.
Why are low grade ores being used more than high grade ores?
High grade ores contain relatively high concentrations of metals but are limited resources and are becoming scarce and so low grade ores are what is left.
What is a disadvantage of using alternative methods of extraction?
They are slower compared to traditional methods such as mining ore.
What is a life cycle assessment?
It assesses the environmental impact of four different stages in the lifetime of a product and of the transport and distribution used between them.
What are the aims of doing an LCA?
Researching alternative methods of manufacture, maintenance and disposal. This includes adapting the designs and sources of energy for a product.
Describe the process of an LCA.
What are the limits of an LCA?
Some aspects cannot be easily quantified such as the effects of some pollutants therefore it can be quite subjective.
How can an LCA be misused?
Manufacturers might use part of an LCA or choose a more favourable LCA in order to support claims about their product or process in advertising.
How can limited resources be conserved?
Using less of these resources
Reusing products where possible
Recycling products and their parts when they have reached the end of their useful lives
When iron is extracted from iron ore in a blast furnace, some scrap steel may be added to the liquid iron. Why?
It recycles used steel which reduces the amount or iron ore that must be used.
Why are broken bathroom tiles more difficult to recycle than plastic shampoo bottles?
Tiles are made from clay ceramics which cannot be melted and reformed but most plastics can be melted and reformed into new products.
Explain the process of recycling glass.
Collecting and sorting
Crushing
Melting and moulding
New products
Explain the process of recycling metal.
Collecting and sorting
Melting
Recasting
New products
