Chemistry-Metals and their extraction

What is a metal ore?

A rock which contains enough concentration of metal to make it worthwhile extracting the metal from it

What are metal ores?

finite and non renewable

When were oxides and sulfides formed?

sulfides-when there were a lot of sulfur from volcanic activity

oxides-when photosynthesis released large amounts of oxygen

What is Aluminiums and irons ore and chemical formulae?

Aluminium-bauxite-Al2O3

Iron-hematite-Fe2O3

What is the reactivity series?

People (potassium) --------------extract by electrolysis

Sell (sodium)

Clothes (calcium)

Magezines (magnesium)

And (aluminium)

Chanel (carbon)

Zara (zinc)-----------------------extract by reduction with carbon or carbon monoxide

Is (iron)

Trending (tin)

Loads (lead)

Hollister (hydrogen)

Cant (copper)----------------------native (uncombined)

Sell (silver)

Good (gold)

Products (platinum)

What is reduction, oxidation and elecrolysis?

Reduction-removes oxygen

Oxidation-gaining oxygen

Elecrolysis-using electricity to extract a metal

What is a displacement reaction?

A reaction in which a more reactive element takes the place of a less reactive element in a compound

What is an oxidation reaction?

The more reactive metal takes the oxygen off the less reactive

What does a blast furnace look like?

Top -Iron ore, coke and limestone

Bottom right of first section-Hot air

second section-Slag outlet

last section-Iron outlet

What are the things used in the blast furnace?

Iron ore-source of iron

Coke-fuel and source of carbon monoxide for reduction

Limestone-to remove impurities (forms slag)

Hot air-Provides oxygen for coke to burn

What is the 1st step of the blast furnace?

COMBUSTION

Carbon + Oxygen -----> Carbon monoxide 2C (s) O2 (g) 2CO (g)

What is the 2nd step of the blast furnace?

REDUCTION

Iron(III) oxide + Carbon monoxide -----> Iron + Carbon dioxide Fe2O3 (s) 3CO (g) 2Fe (I) 3CO2 (g)

What is the 3rd step of the blast furnace?

THERMAL DECOMPOSITION

Calcium carbonate -----> Calcium oxide + Carbon dioxide CaCO3 (s) CaO (s) CO2 (g)

What is the 4th step of the blast furnace?

NEUTRALISATION

Calcium oxide + Silicon dioxide (silica) -----> Calcium silicate CaO (s) SiO2 (s) CaSiO3 (l)

What needs to happen for electrolysis to work?

The ions must be free to move, which can only happen if they are dissolved in water or molten

What happens at the positive anode (left)?

It will attract negatively charged non-metal ions. These ions will then lose electrons through oxidation.

What is the formula for oxidation in the positive anode (left)?

2Br- ——> Br2 + 2e-

What happens at the negative cathode (right)?

It will attract positively charged metal ions. These will then gain electrons through reduction

What is the formula for reduction in the negative cathode (right)?

Pb2+ + 2e- ——> 2Pb

What are the electrodes made of?

graphite

What happens to oxidation and reduction when oxygen is not present?

Oxidation = loss of electrons

Reduction = gain of electrons

How do you extract metals that are very reactive?

Melt it first so electricity can pass through it

What does a diagram of electrolysis on something very reactive look like ?

3 bars in middle-positive electrode anode

Gas surrounding bars-oxygen

Liquid surrounding bars-molten aluminium oxide (electrolyte)

Liquid at bottom-molten aluminium

Bar on outside-negative electrode cathode

What happens at the cathode?

Al3+ +3e- ——> 3 Al

What happens at the anode?

2O2- ——> O2 + 4e-

What is wrong with extracting a metal that is very reactive?

It is expensive because it has a high melting point and carbon dioxide is formed so they need to be replaced which is also expensive

What are some factors affecting the location of industrial plants?

-near coast to import raw materials

-site away from built up areas

-Town or city with commuting distance to accommodate employees

How do we increase the lifetime of metal ores?

Recycle metals. This means less electrical consumption which means there are less greenhouse gas emissions. However, the environment is spoilt by quarrying

What are the functions of steel?

It is harder and stronger than iron and less likely to rust

What is an alloy?

A mixture of two or more elements

What are the uses of aluminium?

-in the aerospace industry, because of it low density

-In high voltage powerlines, because it is a good conductor of electricity

What is copper used for?

-electrical wiring as its ductile

-plumbing as it does not react with water

What is titanium used for?

Hip, joints and fighter aircraft because it is hard strong and low density

What is the colour of a compound with Fe2+ ?

Pale green

What is the colour of a compound with Fe3+ ?

Brown

What is the colour of a compound with Cu2+ ?

Blue

What is the overall equation for the electrolysis of water?

2H2O --> 2H2 + O2

What is the equation for the cathode in the electrolysis of water?

2H+ + 2e- ——>H2

What is the equation for the anode in the electrolysis of water?

4OH- - 4e- ——>2O2 + 2H+

Why is twice the volume of hydrogen made in the electrolysis of water?

Because the formula of water is H2O

How does electroplating work?

The negative electrode should be the object to be electroplated. The positive electrode should be the metal that you want to coat the object with. The electrolyte should be a solution of the coating metal, such as its metal nitrate or sulfate.

How do you speed up electroplating?

Increase the current by increasing the concentration of the electrolyte

What can sodium chloride also be known as?

Brine and salty water

In the electrolysis of sodium chloride, why is it important to use unreactive materials for electrodes?

Because the products are reactive