Flashcards in Unit 10-Using resources Deck (63):
What are ceramics?
Non-metal solids with high melting points that aren't made from carbon based compounds.
What can some ceramics be made from?
Why is clay useful?
It is a soft material that can be moulded into different shapes.
What happens when clay is fired at high temperatures?
It hardens to form clay ceramic.
What is clay ideal for?
Pottery and bricks.
What is another example of a ceramic that isn't clay?
Why is glass useful?
It is transparent, can be moulded when hot and can be brittle when thin.
What is most of the glass that is made?
Soda lime glass.
How is soda lime glass made?
By heating a mixture limestone,sand and sodium carbonate until it melts.It then cools to form glass.
Which glass has a higher melting point than soda-lime glass?
How is borosilicate glass made?
The same way as soda-lime glass but with sand and boron-trioxide.
What are composites made of?
Composites are made of one material embedded in another.
What are fibres or fragments also known as?
What are fibres or fragments surrounded by?
A matrix which acts as a binder.
What do the properties of the composite depend on?
The material that it is made from.
What does fibreglass consist of?
Fibres of glass embedded in a matrix made of polymer.
What are some properties of fibreglass?
It has a low density but is very strong.
What can fibre glass be used for?
Skis, boats and surfboards.
Do carbon fibre composites also have a polymer matrix?
What are the reinforcements made from in carbon fibre composites?
Carbon nanotubes or or long chains of carbon atoms bonded together.
What are the properties of carbon fibre composites?
They are strong and light.
What can carbon fibre composites be used for?
Aerospace and sports car manufacturing.
What is concrete made out of?
Aggregate embedded in cement.
What is a property of cement?
It is very strong.
What is cement used for?
It is used as a building material for pavements.
What is wood?
A natural composite of cellulose fibres held together by an organic polymer matrix.
What are the two different properties of polymers?
Some have a low density and others have a high density.
How is low density polyethene made?
It is made from ethene at moderate temperatures under high pressure with a catalyst.
How is high density polyethene made?
It is made from ethene but at a lower temperature and pressure with a different catalyst.
What can low density polyethene be used for?
Bags and bottles.
Why are low density polyethenes useful?
They are flexible.
What can high density polyethene be useful for?
Water tanks and drainpipes.
Why are high density polyethenes useful?
They are more rigid than low density polyethene.
What is corrosion?
When metals react with substances in their environment and are gradually destroyed.
Does iron erode easily?
In order to rust what must the conditions be like?
The metal must be in contact with oxygen and water, which are present in air.
How can you prevent rusting?
-painting/coating with plastic.
How is painting/coating with plastic useful?
It stops rust, decorative.
How does electroplating work?
It uses electrolysis to reduce metal ions onto an iron electrode and so it can coat the iron with a layer of a different metal that won't corrode away.
How is oiling/greasing useful?
It is useful for when objects are moving to stop rust.
What are natural resources?
Resources that form without human input.
What are finite resources?
Resources that aren't formed quick enough so that they can be considered replaceable.
Give an example of a finite resource...
What is sustainable development?
An approach to development that takes account the needs of present society while not damaging the lives of future generations.
What is a life cycle assessment?
An assessment that looks at a product's life to asses the impact it will have on the environment.
What is a disadvantage to a life cycle assessment?
It can be biased.
What is potable water?
Water that has been treated or is naturally safe for humans to drink.
Why isn’t potable water pure?
It contains other dissolved substances.
What are the most important features of potable water?
-The levels of salts aren’t too high.
-It’s PH is between 6.5 and 8.5.
-That there aren’t any bacteria or microbes in it.
What are the two main steps to making potable water?
Filtration then sterilisation.
How is the water filtered to make it potable?
A wire mesh traps large twigs etc... then gravel and sand beds filter out any other solid bits.
How can the water be sterilised?
By bulling chlorine gas through it or by using ozone or ultraviolet light.
What must be used to create potable water in areas where there’s not enough groundwater?
Desalination of sea water.
What can be used to desalinate sea water?
How do you desalinate sea water?
1)Test the PH with a PH meter ,then neutralise it through titration.
2)Test the water for the presence of sodium chloride by doing a flame test and the white precipitate test.
3)Pour the water into a distillation apparatus to distil it,leaving the salts in the flask.
4)Retest the PH and the presence of sodium chloride ions.
Why should you use a PH meter instead of an indicator min the distillation of sea water into potable water?
It won’t contaminate the water.
What are the disadvantages to making potable water from sea water?
It is not practical for large quantities of water and is really expensive.
What is the haber process?
An industrial process that is used to make ammonia from hydrogen and nitrogen.
Why is the habit process good for making ammonia?
The reactants aren’t too difficult or expensive to obtain.
Is the barber process reversible?
Why are NPK fertilisers useful?
They provide plants with the essential elements for growth.
What does leaching mean?
The use of dilute acid to produce soluble metal compounds from insoluble metal compounds.