P2: Using Resources Flashcards
What is the term for the corrosion of iron?
Rusting
What is rusting?
The corrosion of iron. Rust forms on the surface of it.
What is required for rust?
Iron, oxygen and water.
What is the word equation for rust?
Iron + Oxygen + Water —> Hydrated Iron Oxide
What are the three methods of preventing rust?
Casting the iron in something, galvanisation, sacrificial protection.
What can we coat the iron in to prevent rusting?
Paint, oil, grease, plastic, a less or more reactive metal.
What is galvanisation?
Dipping the iron in steel or zinc.
How can we apply a metal to coat iron?
Electroplating
Why do we galvanise the iron in zinc?
Zinc is more reactive than the iron/steel, so it loses electrons, becoming oxidised instead. Any oxygen or water reacts with the zinc, sacrificing itself.
What is sacrificial protection?
Coating the iron in something, with that thing being worn down/used up over time. Galvanisation is a form of sacrificial protection.
What is bronze?
Copper and tin.
What are the properties of bronze?
Tough, resistant to corrosion.
What is brass?
Copper and zinc.
What are the properties of brass?
Hard, workable. Used for musical instruments.
What are aluminium alloy’s properties?
Light-weight, strong.
What are gold alloys made of?
Gold and typically copper.
What are gold alloys used for?
Jewellery
What are the properties of high carbon steels?
Strong, brittle.
What is stainless steel made of?
Iron, chromium, nickel.
What are the properties of low carbon steels?
Softer, easier to shape.
What are the properties of stainless steel?
Resistant to corrosion, expensive.
What is the structure of low density polyethene?
Polymer chains are randomly branched, cannot pack closely together (hence its lower density).
How is low density poly ethene made?
Using high pressures and a trace of oxygen.
How is high density polyethene made?
Using a catalyst at 50°C and slightly raised pressure.
What is the structure of high density polyethene?
Made up of straighter chains, can pack more closely together, has a higher softening temperature and is stronger than low density polyethene.
Describe the structure of a thermosetting polymer.
Chains fitted together by strong covalent bonds. Cross links. Don’t melt easily.
What do thermosetting polymers make?
Harder plastics with denser structures.
Describe the structure of a thermosoftening polymer.
Tangled web of polymer chains that are relatively easy to separate. Melts easily when heated. Covalent bonding with intermolecular forces.
What do thermosoftening polymers make?
Softer plastics with less dense structures.
What are the two types of glass?
Sodalime glass and borosilicate glass.
Describe the structure and general properties of glass.
Very disordered. Unreactive, inert and acts as a good insulator.
What is borosilicate glass made from?
Sand, borontrioxide.
How is sodalime glass made?
Heating a mix of sand, sodium carbonate and limestone.
What are the properties and uses of sodalime glass?
Lower melting and boiling points, used for drink bottles, spectacle lenses. Good for recycling.
Describe the properties and uses of borosilicate glass.
Higher melting point, brittle, doesn’t conduct electricity. Used for ovenware, test tubes and beakers.
Describe the structure and properties of ceramics.
Hard, doesn’t conduct electricity, brittle, inert, has both ionic and covalent bonds, giant, resistant to chemical attack, insulator.
How are ceramics made?
Shaping wet clay and heating it in a furnace.
List the uses of ceramics.
Pottery, toilets, bricks, tiles, crockery, sinks, baths.
Describe the properties of a composite.
They depend on the properties of the materials placed inside. Typically flexible, waterproof with a low density.
Describe the making of a composite.
Made of two materials, with one acting as a binder for the other, improving a desirable property that neither of the original materials could offer alone. Embed fibres or fragments into the binder.
Describe the uses of composites.
Kayaks, reinforced concrete, bikes, planes, plywood.
What is phytomining?
Using plants to absorb metal compounds from the ground using their roots, then burning the plants to produce an ash containing a high concentration of the metal compounds
What are the benefits of phytomining?
-Reduces the need to obtain new ore by mining
-Conserves limited supplies of high-grade ores
-Reduces the amount of rock waste that must be disposed of after traditional mining
What is the problem with bioleaching?
Produces toxic substances including sulfuric acid, which damage the environment.
What is bioleaching?
Using bacteria to extract metals from their ores. They break down low-grade ores and produce an acidic solution containing copper ions.
What is water that is safe to drink called?
Potable water.
What is pure water?
Water that only contains H20, with no other dissolved substances
What is potable water?
Water that is safe to drink
What is the difference between potable water and pure water?
Potable water is safe to drink and contains dissolved substances
Pure water contains no other dissolved substances
Give examples of water sources for potable water
Rainfalls, rivers, reservoirs
What is the second stage of producing potable water?
Sterilising with chlorine, ozone or UV light. Kills microorganisms and bacteria
What is the first stage of producing potable water?
Passing the water through filter beds, which filter out any solids
What is the process done to sea water when an area doesn’t have much fresh water to produce potable water?
Desalination
Define desalination
The removal of salt from a solution
What are the two methods of desalination?
Distillation and reverse osmosis.
How does distillation work?
You heat up a beaker containing salt water, and wait until the water evaporates. The water vapour escapes the beaker and travels through a condenser, where it evaporates to form water as a liquid again. Produces pure water.
How does reverse osmosis work?
Moves water from a higher solute concentration to a lower solute concentration. Requires energy to move the water against its concentration gradient.
What is a problem with reverse osmosis?
Requires a lot of energy
What is the problem with waste water?
Contains organic matter, harmful chemicals and harmful microbes. Not safe to release into the environment. Must be treated.
What is a problem with distillation?
Requires a lot of energy
What must happen to waste water before it is released into the environment?
Must be treated.
What is the third step in treating waste water?
The effluent undergoes aerobic biological treatment. Bacteria uses oxygen to break down any organic matter left in the effluent. Effluent is now water, and is released back into the environment.
Sewage sludge undergoes anaerobic digestion, with bacteria breaking down the sludge without using any oxygen. This is used as fertiliser.
What is the first step in treating waste water?
Screening out the grit and other solids.
What is the second step in treating waste water?
Water is passed through sedimentation tanks. These tanks split the waste water into sewage sludge and effluent.
What happens to the effluent in waste water treatment once it is treated?
Released back into the environment.
What happens to the sewage sludge in waste water treatment once it has been digested?
Used as fertiliser.
What chemical is added to the water to reduce tooth decay?
Fluorine
What are the 4 factors that need to be taken into account during an LCA analysis?
-Raw materials
-Manufacturing
-Use and operation
-Disposal
Describe the raw materials used for making paper bags.
Made of recycled paper or trees
-Making paper requires a lot of water
-Recycling paper requires less energy than making it
-Both use less energy than making plastics
-Cutting down trees destroys habitats
Describe the raw materials used for making plastic bags
Need crude oil
-Which is a finite resource
-Requires a lot of energy to process.
-Extracting crude oil releases greenhouse gases into the atmosphere
Describe the manufacturing process for paper bags.
-Pulping paper uses a lot of energy, water and sulphur dioxide
-Produces waste
-Expensive
Describe the manufacturing process for plastic bags.
-Fractional distillation, cracking and polymerisation.
-Not much waste
-Cheap to manufacture
Describe the usage of plastic bags
-Flimsy, but reusable
Describe the usage of paper bags
-Flimsy, easy to tear
-Most aren’t reusable
Describe the disposal of paper bags.
-Biodegradable
-Non-toxic
-Easily recycled
Describe the disposal of plastic bags.
-Can be recycled, but it costly and produces pollution.
-Not biodegradable
-Takes up space, usually placed in landfill
What is the name of the most important group of fertilisers?
NPK Fertilisers. This stands for Nitrogen, Phosphate, Potassium.
Where are NPK fertilisers produced?
In large industrial facilities.
What are NPK fertilisers?
Formulations of different salts.
List the process for making nitrogen fertilisers.
AMMONIA (produced by the Haber process)
NITRIC ACID
AMMONIUM NITRATE (nitric acid reacted with more ammonia)
List the process for potassium fertilisers.
-Comes from the salts POTASSIUM CHLORIDE OR POTASSIUM SULFATE
-Both are mined from the ground and can be used directly without processing.
List the three acids phosphate rock is treated with.
Nitric acid, phosphoric acid, sulfuric acid.
List the processes for phosphorus fertilisers.
-Phosphate rock has to be chemically processed before being used in a fertiliser.
-3 different methods.
-PHOSPHATE ROCK, treated with phosphoric acid —> TRIPLE SUPERPHOSPHATE
-PHOSPHATE ROCK, treated with sulfuric acid —> CALCIUM PHOSPHATE + CALCIUM SULFATE (this mixture is called SINGLE SUPERPHOSPHATE)
-PHOSPHATE ROCK, treated with nitric acid —> PHOSPHORIC ACID + CALCIUM NITRATE, phosphoric acid neutralised with ammonia —> AMMONIUM PHOSPHATE
List the three products of phosphorus treatment:
-Nitric acid: Ammonium phosphate
-Phosphoric acid: Triple superphosphate
-Sulfuric acid: Single Superphosphate
What is the Haber process used for?
Making ammonia.
Where is Ammonia formed?
In a reversible reaction between Nitrogen and Hydrogen.
What is ammonia used to make?
Nitrogen-based fertilisers.
Where do we get the Nitrogen and Hydrogen used for the Haber process from?
Natural gas.
What are the specific conditions for the Haber process to create ammonia
-450 degrees Celsius to increase the rate of reaction, while compromising the yield.
-High pressure of around 200 atmospheres to shift the equilibrium position to the right and increase the yield of ammonia.
-Iron catalyst needed needed to speed up the rate of the reaction.
Describe the steps of the Haber process.
-Nitrogen and hydrogen are pumped through pipes
-The pressure of the mixture of gases is increased to 200 atmospheres, the temperature heated to 450 degrees Celsius and passed through a tank containing an iron catalyst.
-The reaction mixture is cooled so that ammonia liquifies and can be removed
-Unreacted Nitrogen and Hydrogen are passed through a pipe to be recycled and brought back to the beginning of the station.
How can you tell if a substance is pure?
It will have a very specific melting and boiling point.
Explain why the unreacted Hydrogen and Nitrogen are recycled in the Haber process.
Recycling the unused reactants saves money and increases the effective (overall) yield.
