Topc 10 - Using Resources Flashcards
What is the Hager process?
Used to manufacture ammonia form nitrogen and hydrogen
What is rather equation for the haber process?
N2 + 3H2 <-> 2NH3 and heat
What conditions are needed in the haber process?
200 atmospheres
450 degrees
Iron catalyst
What is the ammonia in the haber process used for?
Nitrogen based fertilisers
Where does the nitrogen come from in the haber process?
The air
Where does the hydrogen come from in the haber process?
Hydrocarbons like methane
How does the haber process work?
Nitrogen and hydrogen are fed into a vessel where the controls are correct, a iron catalyst is used to make ammonia, the mixture is reversible so some of it will reverse.
The ammonia is cooled into liquid ammonia and the reactants will be recycled
Why are the conditions for the haber process specific?
Temperature - exothermic means a lower temp needed to favour forward reaction, although high enough for reaction rate
Pressure - quicker reaction rate but limited by cost and safety of maintaining a high pressure
What is a fertiliser?
A substance applied to the soil in order to supply plants with nutrients
What is a formulation?
A mixture that has been designed as a useful product, made by combining certain chemicals in a certain ratio
What are the three parts in a NPK fertiliser
Nitrogen
Phosphorus
Potassium
How do you get the nitrogen for npk fertilisers?
Main source is ammonia. Ammonia can react with water to make nitric acid
How do you get phosphorus for npk fertilisers?
Can be mined from the ground as rock. However, they are insoluble and need to be reacted with acids to produce salts
What happens when you react phosphate rock with nitric acid?
Phosphoric acid and calcium nitrate
What happens when you react phosphate rock with sulfuric acid?
Calcium sulphate and Calum phosphate
What happens when you react phosphate rock with phosphoric acid?
Calcium phosphate
How do you get potassium for npk fertilisers?
Potassium can be found in potassium sulphate or potassium chloride. It can be mined and used directly
How do humans use earths resources?
Warmth, shelter, food and transport
What is sustainable development?
Development that meets the needs of current generations without comprising the ability of future generations to meet their own needs
What is potable water?
Water that is safe to drink. It’s not chemically pure because it contains dissolved substances.
Where do we get drinking water from in the UK?
Rain provides water with low levels of dissolves substances that collects in the ground and in lakes and rivers
How does the UK turn rain into potable water?
Choosing an appropriate source
Pass through wire mesh to filter big things out
Passing the water through filter beds - filters out small solids
Sterilising
Why and how do we sterilise water?
To kill any microbes
Bubble chlorine gas through it, expose it to ozone or UV light
Why May fluorine be added to water?
Improve dental health
What process is used when fresh water is limited?
Desalination
What is desalination?
A process which removes salt from sea water to make drinkable water
What are the two ways desalination can be done?
- by simple distillation
- by passing water through membranes that use reverse osmosis
What are the negatives of desalination?
Requires lots of money for energy.
What are the three types of waste water?
Sewage
Agricultural
Insutrial
Why does industrial waste need treating?
Remove organic matter and harmful chemicals
Why does sewage and agricultural waste need treating?
Remove organic matter or harmful microbes
What are the four main steps to treating waste water?
Screening
Sedimentation
Anaerobic digestion of sewage sludge
Aerobic biological treatment of affluent
What does screening waste treatment mean?
Remove any large parts and objects like litter and water bottles
What does sedimentation mean in waste treatment?
Have user solid sink to bottom - sewage sludge
Light part at top - effluent
How do they break down sewage sludge?
Anaerobic digestion
How do they break down sewage effluent?
Aerobic biological treatment
What are the two alternative ways of extracting copper from low grade ores?
Bioleaching
Phytomining
What is phytomining?
Uses plants to absorb metal compound - copper compounds. The plants are harvested and then burnt to produce ash that is reich in the metal compound
What is bioleaching?
Bioleaching she’s bacteria to produce leachate solutions that contain metal compounds!
Why are LCAs carried out?
To assess the environmental impact of products
What stages do LCA assessments evaluate?
- extracting and processing raw materials
- manufacturing and packaging
- use and operation
-disposal at the end of its lifetime
