Using Resources Flashcards
Is potable ware pure?
No bc it contains dissolved substances
In the uk, the most potable water is produced by:
- choosing an appropriate source of fresh water
- passing the water through filter beds
- sterilising
Which sterilising agents are used for potable water?
Chlorine, ozone and ultraviolet light
What can you do if supplies of fresh water is limited?
Desalination of salty water or sea water may be required
Desalination can be done by
Distillation or processes that use membranes eg reverse osmosis
Sewage treatments include:
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- anaerobic biological treatment of effluent
What new ways can you extract metals from low grade ores?
1) phytomining: harvesting plants and burning them to produce ash that contains metal compounds
2) bioleaching: uses bacteria to produce leachate solutions that contain metal compounds
What is corrosion?
The destruction of materials by chemical reactions with substances in the environment
How to prevent corrosion?
By applying a coating hat acts as a barrier eg greasing, electroplating or painting
What is sacrificial protection?
When a reactive metal is coated with a more reactive metal
24k gold = ?
100% gold
What are steels?
Alloys of iron that contain specific amounts of carbon and other metals
Aluminium alloys are
Low density
What if ammonia used for?
Producing nitrogen-based fertilisers
What happens during the Haber Process?
The purified gases are passed over a catalyst of iron at a high temperature (about 450°C) and a high pressure (about 200 atmospheres). Some of the hydrogen and nitrogen reacts to form ammonia. The reaction is reversible so some of the ammonia produced breaks down into nitrogen and hydrogen. On cooling, the ammonia lique es and is removed. The remaining hydrogen and nitrogen are recycled.
