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Crust and lithosphereRigid. Hard.
Lighter elements. Floats on mantle.
Upper Mantle –Asthenosphere – partially molten. Soft.
Lower Mantle – Semi-solid. Plastic.
Inner coreSolid. Mainly iron with some nickel
Outer Core.Fluid – like water
Creates our magnetic field
• Runny lava
• Makes a volcano with very shallow sides
• No explosions or gases
• Calm
• Basalt rock – low silica
• E.g. hawaii
• Acidic lava – really thick
• Very gassy – gas trapped in thick lava
• Explosive
• Lays of lava, then rock and ash
• Sticky lava doesn’t flow far away before cooling
Why do people live near volcanoes?
Ash makes soil very fertile so people believe the benefits
outweigh the risks
To start…Which picture goes with which name of construction material?
Iron (Steel)
Concrete
Marble
Limestone Granite
Aggregate
Iron (Steel)
ConcreteMarble
LimestoneGranite Aggregate
Construction materials – raw materials
Iron is pretty soft. Its made harder by making it into an alloy. Iron and Carbon make
STEEL which is REALLY strong.
There is LOTS and LOTS of iron
so its really CHEAP
Concrete is man made rock. Its made
by mixing:•Cement
•Sand •Aggregate (gravel)
•Water
Cement and concrete
• Cement is calcium carbonate (limestone) which has been thermally decomposed with clay
CaCO3 CaO + CO2
• Concrete is a cement, water and gravel. This makes a stronger construction material which is hard and strong under compression (being squashed)
• Concrete has lots of components going into is, where as cement is just two
Copper
• Copper derivative is removed from the ground as an ‘ore’
• Copper ore = malachite (copper carbonate)
• Ores of metals are impure and have to be processed in order to get pure metal from them
Step 1 - Reduction of Copper Carbonate
Complete your sheet during the discussion
http://www.youtube.com/watch?v=TxbEgcjmhqo
Step 2 – Reduction of copper oxide
Copper oxide is reduced – oxygen is taken away.
Product is impure copper
http://www.youtube.com/watch?v=6nEt6cW_GSw
Step 3 - Using electrolysis to purify copper
http://www.bbc.co.uk/schools/gcsebitesize/science/
add_aqa_pre_2011/ions/electrolysisrev3.shtml
Purification apparatus
Pure copper becomes coated in copper
Impure copper dissolves
Electrolyte - Copper sulfate
Anode (A for add)
Cathode
Opposites attract
Positive ions (cations) travel to the negative electrode (cathode)
Negative ions (anions) travel to the positive electrode (anode)
Half equationsOxidation is loss of electrons
Reduction is gain of electrons
You will understand these more in later (C4) topics but you do need to know them:
•Ions from the copper sulphate solution are reduced (gain electrons)
Cu2+ + 2e- Cu
•The copper anode dissolves putting copper ions back into solution – oxidation (electrons lost)
Cu - 2e- Cu2+
Copy the table below. Working with a partner, complete as much of the table as you can.
Metal Properties Uses
Aluminium
Copper
Gold
Steel
Low density, strong, resistant to corrosion, good conductor of electricity
Good conductor of electricity, resistant to corrosion, easily shaped, flexible
Shiny, very resistant to corrosion, very unreactive, soft, easily shaped
Very strong, very dense.
Lightweight structures, aircraft, drinks cans, high voltage cables.
Electrical wiring, water pipes.
Jewellery.
Large structures and heavy duty engineering such as bridges, trains, cars etc.
In pure metals the atoms arrange themselves closely together into regular patterns. This makes
them dense and also gives them many of their other useful properties.
The layer arrangement of the atoms allows the metals to change shape if a force is applied. The layers can slip over each other.
This can be useful if you want to shape the metal but not so useful if you want it to resist the force and be strong.
By mixing two or more metals together the regular arrangement of the atoms is disrupted. This prevents the atoms forming layers and makes it harder for the atoms to slide over each other. The alloy is stronger than the pure metals.
Metal B
Metal A
Smart alloys
These are alloys that can ‘remember’ their original shape. If they are deformed they can return to their
original shape.
Shape memory glasses Shape memory Stent to keep a blocked blood
vessel open
Smart alloys
Examples include nitinol – alloy of nickel and titanium
Shape memory glasses Shape memory Stent to keep a blocked blood
vessel open
• Rusting is an example of an oxidation reaction, i.e. a reaction where oxygen is added to a substance.
• Rusting needs iron, water and oxygen (air). Rusting happens even faster when the water is salty or acidic.
• Aluminium doesn’t react and corrode in air and water. Instead it quickly forms a protective layer of aluminium oxide. This layer stops any more air or water from going into contact with the metal. This built-in protection will not flake off.
• Oxygen is added to the iron in the presence of water:
Rusting conditions
iron + oxygen + water hydrates iron (III) oxide
• Reactivity series
• Tells us about how reactive metals are and what they react with
• Most metals will corrode over a period of time if kept in water/exposed to oxygen
Corrosion of other metals
• Conditions for corrosion are moisture, air and acidic or alkaline for all metals.
• Gold and silver – little or no corrosion.
• Copper, zinc and aluminium oxide layer strengthens.
• Iron goes rusty, orange and weak.
Corrosion of other metals
Ammonia
• Ammonia (NH3) is made in the Haber process
• The nitrogen comes from the air (78%)
• The hydrogen comes from natural gas or from cracking oil fractions (alkanes alkene + hydrogen)
• The Haber process was developed by Fritz Haber in 1908 and is still used today
Ammonia
• The Haber process uses a catalyst of iron – speeds up the reaction AND can be recovered at the end
• The Haber process has 2 reactions because the reaction is reversible:
Nitrogen + hydrogen Ammonia
Ammonia nitrogen + hydrogen
The Haber process
• Nitrogen is vital for the growth of crops
• The production of fertilisers starts with the Haber process
• The process must be as efficient as possible so ammonia can be made in large quantities
• Conditions have to be tightly controlled
The Haber process
Conditions for the Haber process:
•An iron catalyst
•A high pressure (200 atmospheres)
•A temperature (450°C)
•A recycling system – why do you think this is necessary?
The Haber process
Any hydrogen and nitrogen that are not used in the reaction are recycled and fed back into the reaction
The gaseous ammonia is collected, cooled and liquified
The Haber process
Conditions of the Haber process
• The ‘yield’ of a reaction is how much is produced from the reactants you put in
• As the reaction is reversible, the % yield can never be 100% because once it has been made, the products will remake the reactants!
• An example of % yield would be: 50g of ammonia should be made form the reaction but only 35g were actually produced – what is the % yield?
Conditions of the Haber process
The Haber process % yield is not as high as it could be:
•A higher pressure would increase %yield•A higher temperature would decrease % yield (however, high temperatures do increase reactions)•450°C is the optimum temperature and makes the most ammonia in a day•Catalysts – no affect on the yield, only make the reaction happen quicker
http://www.youtube.com/watch?v=kIw7KwoXJv0
Types of fertilisers
1. Natural (organic) fertilisers
2. Artificial (inorganic) fertilisers
• Dead and decaying plants
• Mined from rocks and blended to give the right mix of nutrients
• NPK – nitrogen, phosphorous, potassium
What properties would you want in a fertiliser and why?
Soluble
Long lasting
Stay in soil
Easy to store – in pellet form before being dissolved in water
Eutrophication
Keywords:
EutrophicationSolublePhotosynthesisAlgae bloomDecomposersAerobic respiration
Acids and alkalis (bases)• When an acid and an alkali (base) is reacted, we get
a neutralisation reaction
• Neutralisation means the acid becomes more alkaline and moves towards pH 7
• The name of the product depends on the acid and the alkali that goes into the reactionAcid Alkali Fertiliser
Nitric acid Potassium hydroxide Potassium nitrate
Nitric acid Ammonia
Sulphuric acid Ammonia
Ammonium phosphate
Any fertiliser with nitrogen in is called a
NITROGENOUS FERTILISER
Titrations• Titrations is when an acid is added to an alkali until
neutralisation occurs (becomes pH7)
• A titration is used to find the ‘end point’ or the point where the solution is neutral
• A pH indicator is used and when it goes green/changes colour – it shows neutralisation has taken place
• You might need to draw the equipment…
Salt extraction
How could salt extraction damage the environment?
The facts
Rock salt is extracted from salt mines
Salt mines are found under the surface of the Earth
Much of the salt is stored in rocks
All of the salt has to be transported to be processed and purified
Example – salt mining costs and environmental impact
Salt
In pairs, have a conversation about what these three photos are telling you. Points to consider: What are the photos of? What properties do they have? What are the similarities / differences between them.
Structure of Ionic Compounds
• Giant Lattice Structure
• Made of crystals• Positive ions &
Negative ions• Strong
Electrostatic Forces
The structure affects the properties of the ionic compound.
The structure affects the properties of the ionic compound.
In an ionic compound, millions and millions of ions are packed together in a regular 3D arrangement, joined by ionic bonds.
Positive ion
(CATION)
Negative ion (ANION)
Strong ionic bonds (electrostatic attraction
between oppositely charged ions)
There are very strong chemical bonds between all the ions.
A single crystal of salt is one GIANT IONIC LATTICE which is why salt crystals tend to be cuboid in shape.
Ionic compounds in solution
Dissolve in
water
• What is different about the arrangement of ions before and after dissolving?
• Why can a solution of an ionic compound conduct electricity when a solid can’t?
NegativeCathode
PositiveAnode
D.C.current
+ -
Na+
Na+Cl-
Cl-H+
H+
OH-
OH-
At the anode
Cl2
There are lots of chloride ions in brine.They are attracted to the anode first
The chloride ions lose electrons and become chlorine gas
2Cl- Cl2 + 2e-
OXIDATION
The hydroxide ions get left behind in solution. There aren’t enough to discharge.
2e-
NegativeCathode
PositiveAnode
D.C.current
+ -
Na+
Na+Cl-
Cl-H+
H+
OH-
OH-
At the cathode
2e-
The electrons get pumped into the cathode.
Positive ions are attracted to it.
Hydrogen ions get to the cathode before the sodium ions.
Hydrogen gas is discharged.
2H+ + 2e- H2Reduction
Sodium ions are left behind in solution.
H2
NegativeCathode
PositiveAnode
D.C.current
+ -
Na+
Na+Cl-
Cl-H+
H+
OH-
OH-
Where will the ions go?
H2
Cl22e-
Products
• The three main products are:
• Hydrogen gas
• Chlorine gas (bleaches litmus paper)
• Sodium hydroxide solution
Cl2
H2
Na+ OH-
Products uses
• Hydrogen gas – Haber process and manufacturing of margarine
• Chlorine gas – sterilise drinking water, make bleach, as well as PVC (plastic)
• Sodium hydroxide solution – used to make soap