1_2.1 and 2.2_extracting metals extracting iron

7/27/2019 1_2.1 and 2.2_Extracting Metals Extracting Iron

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GCSE Core Chemistry

Exam tip; You DO NOTneed to remember technical detailsof the blast furnace

Prior Learning;

a) Understand what happens to carbonates when

they are heatedb) Know that an ore contain a metal mixed with rock

c) Know how to work safely in the laboratory

Keywords:

displacement, electrolysis, ore, native, reduce, coke,

reduced, cast iron


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GCSE Core Chemistry


Learning Objectives:

By the end of the lesson I can:

Explain where metals are obtained from.

Give examples of how metals are extracted from the Earth.Metals that are less react ive than carbon can be extracted from their

oxides by reduct ion in carbon, for example i ron oxide is reduced in theblast furnace to make iron.

Identify that metals less reactive than carbon can be

extracted by reducing their oxides.

Explain that iron is extracted in a blast furnace.Consider and evaluate the social, economic and

environmental impacts of exploiting metal ores, of using

metals and of recycling metals.


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GCSE Core Chemistry


1. Ores contain enough metal

to make it economic toextract the metal and this

changes over time.

3. Most metals are

found as compounds

that require chemical

reactions to extract the

metal.

2. No metals are naturally

found in the Earth as themetal itself.


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GCSE Core Chemistry


http://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8

SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=en#
http://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=enhttp://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=enhttp://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=enhttp://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=enhttp://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=enhttp://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=enhttp://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=enhttp://video.google.co.uk/videoplay?docid=9009946453212399554&ei=dTz8SrWYLte2-Aat-6TfCg&q=reactivity+series&hl=en


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GCSE Core Chemistry


The Reactiv i ty Series

Metals are arranged in order of how reactive theyare.A more reactive metal will displace a lessreactive one from its compounds.

For example,zinc will displace copper from copper sulfate togive zinc sulfate plus copper.

What is the word and symbol equation?

Zn(s) + CuSO4 (aq) ZnSO4 (aq) + Cu (s)

zinc(s) + copper sulfate(aq) zinc sulfate(aq) + copper (s)

What is this type of reactionGENERALLY called?


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GCSE Core Chemistry


The more vigorously an element forms

compounds the harder it will be to get back

that element from its compounds.

For example, magnesium gives out lots of

heat when it combines with oxygen.

This means we will have to put lots of energy

back to extract magnesium from magnesium

oxide and so it will be hard to extract.


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What about gold?

How would you extract it?

Would this

work?Why?

An ore containing the element Au

The element Au




Potassium

Sodium

CalciumMagnesium

Aluminium

Carbon

Zinc

Iron

Tin

Lead

Copper

Silver

Gold

Platinum

Metals ABOVE CARBON, becauseof their high reactivity, are

extracted by ELECTROLYSIS

Metals BELOW CARBON areextracted by heating them withcarbon in a BLAST FURNACE

These LOW REACTIVITY metals wontneed to be extracted because they areSO unreactive youll find them on theirown, not in a metal oxide. These arepanned for!




REDOX REACTION: Extracting copper from Malachite

Malachite is a mineral known as CopperCarbonate ( CuCo3)

When malachite is heated

with Carbon,

it is reduced (oxygen is removed) to leavebehind copper metal.

Copper Carbonate + Carbon Monoxide Copper metal + Carbon dioxide

What process isneeded to

extract copper?How could you

do it in the lab?
http://en.wikipedia.org/wiki/File:Malachite_Macro_43.jpg




Reduction by carbon

Method

1. Put on your eye protection.

2. Add a spatula (1 cm3) of the metal oxide and carbon to your boilingtube (ratio 1:1)

3. Clamp the boiling tube so that it is sloping. Make sure the tube isclamped close at its open end.

4. Add a loosely fitting mineral wool plug to the open end of boiling tube.5. Light your Bunsen burner.

6. Heat the tube using a hot flame. Direct the tip of the inner blue coneonto the mixture and away from the plastic on the clamps!!!!

7. Observe what happens. Write your observation in your results table.

8. Stop heating and allow the reaction mixture to cool.

AT THIS POINT WE WILL STOP AND CONTINUE IN PERIOD 5

RESULTS TABLE

REACTION OBSERVATIONS

Copper

oxide &

Carbon

Iron

oxide &

Carbon




Removal ofoxygen from

a compound

A list of elementsfrom most to

least reactive

A rock containingenough metal to make it

economic to extract

Unreactive

metals, found

as elements in

nature

Metal ores are

rocks that

Gold, platinum

& silver

Reduction

reactions are

contain enough metal to make extraction economic

to remove oxygen from a metal oxide

native metals

native oreReactivity series

reduction




Prior Learning;

a) Understand what happens to carbonates when

they are heatedb) Know that an ore contain a metal mixed with rock

c) Know how to work safely in the laboratory

Keywords:

displacement, electrolysis, ore, native, reduce, coke,

reduced, cast iron

E d h l d l





By the end of the lesson I can:Explain where metals are obtained from.


oxides by reduct ion in carbon, for example i ron oxide is reduced in the

blast furnace to make iron.



Explain that iron is extracted in a blast furnace.

Consider and evaluate the social, economic andenvironmental impacts of exploiting metal ores, of using


EXT: Explain how electrolysis works and why it is not always used

E D N d b h l d l




continuing on

1. Take an evaporating dish and add about

25 cm3 of sulfuric acid to it.

2. Take your (now cool) reaction mixture

and add it to the acid.

3. Observe what happens. Write your

observation in your results table.

4. Complete word and chemical equations

for your extraction.

E i Y DO NOT d b h i l d il




Type of metal Extraction process Examples

High reactivity (i.e

anything above carbon)

Middle reactivity (i.e.

anything below carbon)

Low reactivity

Reactivity Series

ELECTROLYSIS

Potassium, Sodium,

Calcium, Magnesium,Aluminium

BLAST FURNACE

(heating with

carbon to reduce

their oxides)

Zn, Fe, Sn, Pb, Cu

PHYSICAL

EXTRACTION

Silver, Gold,

Platinum

E ti Y DO NOT d t b t h i l d t il




Which substance is being oxidised? Reduced?

Iron oxide + carbon monoxide iron + carbon dioxide

CaCO3

Fe2O3

C

Chemical: Calcium Carbonate Common: Limestone

Chemical: Iron (III) oxide Common: Haematite

Chemical: Carbon Common: Coke

What are the molecular formulas?

& what do they mean?



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GCSE Core Chemistry


Blast furnace

Write the chemical reactions for the followingstages in the blast furnace.

1. Hot air is blown into the blast furnace

which makes the coke burn and oxidise.

2. At high temperatures, carbon dioxide gas

reacts with more coke and is reduced.

3. The resulting gas reacts with iron (III)

oxide causing it to reduce whilst the gas

oxidises in a redox reaction.

Coke + oxygen gas (forms) carbon dioxide gas

C + O2 (forms) CO2

Carbon dioxide gas + coke (forms) carbon monoxide gas

CO2 + C (forms) CO

Carbon monoxide gas + iron (III) oxide (forms) iron metal

+ carbon dioxide gas

Fe2O3 + 3CO (forms) 2Fe + 3CO2



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GCSE Core Chemistry


Iron Mining

Use you text (p41) and this video toconsider and evaluate the social,

economic and environmental impacts

of exploiting metal ores, of usingmetals and of recycling metals.

http://www.youtube.com/watch?v=ruiydHeuQSQ

(6 marks)

E m ti ; Y DO NOT d t m mb t h i l d t il
http://www.youtube.com/watch?v=ruiydHeuQSQhttp://www.youtube.com/watch?v=ruiydHeuQSQhttp://www.youtube.com/watch?v=ruiydHeuQSQhttp://www.youtube.com/watch?v=ruiydHeuQSQ


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GCSE Core Chemistry


Extracting metals causes

huge amounts of waste.

Copper production discards

99.5% of the extracted ore.

Open-cast mining removes

ores using explosives. It

produces dust and can scar

the landscape. This disused

copper mine in Ajo, Arizona,

measures one mile wide.

Harmful waste gases, including sulfur dioxide, carbon

dioxide and carbon monoxide, are produced by extraction.

Extraction, especially electrolysis, also uses lots of electricity.

Exam tip; You DO NOT need to remember technical details


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GCSE Core Chemistry


New mining techniques can decrease the effects of metal

extraction on the environment.

Leaching uses less electricity than traditional

mining and does not produce waste gases.

Copper ores are treated with and dissolved in

dilute sulfuric acid, producing copper sulfate.

Electrolysis is then used to extract the copper.Certain bacteria can also be used to dissolve

ores and form copper sulfate.

Phytomining uses plants to absorb metals

from the soil. The process can be used to

clean contaminated land. Treating the plants

with certain chemicals increases their ability

to accumulate minerals in their cells.



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GCSE Core Chemistry


Recycling creates less waste and reduces

the number of sites that have to be mined.

Recycling uses up to 95% less electricity

than producing metals from ores.

Metals are easier to recycle than plastic and they retain

their original properties, such as conductivity and hardness.

Recycling costs less than extracting

metals and can be profitable.

One problem is that metallic materials in recycled objects are

often mixtures of different metals. This can mean that

obtaining pure metals from recycling is more expensive, as

it may use more electricity than extracting metals from ores.



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GCSE Core Chemistry




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GCSE Core Chemistry


Electrolysis is a process that uses electricity to

separate the elements in a compound. The word

electrolysis means splitting with electricity.

Aluminium is a reactive metal that is

found in the ore bauxite. It is combined

with oxygen as aluminium oxide.

Electrolysis is used to remove the

oxygen and extract aluminium, whichmeans that reduction takes place.

What is the word equation for the extraction of aluminium?

aluminium oxide aluminium oxygen+

Electrolysis is expensive and so it is only

used to extract reactive metals that cannot

be extracted in other ways.



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GCSE Core Chemistry


Copper is not very reactive and

can occur native but it is rare to

find pure copper. Usually, it is found

combined with other elements,

such as in the ore malachite.

Copper is an excellent conductor and does

not corrode quickly. These properties make

it a good material for wiring and plumbing.

The copper extracted from compounds by reduction with

carbon is impure. Electrolysis can actually be used at this

Only pure copper can be used for electric

wires. Even a very low level of impurities

will reduce coppers conductivity.

stage to remove the impurities and obtain pure copper.



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GCSE Core Chemistry



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GCSE Core Chemistry



By the end of the lesson I can:Explain where metals are obtained from.


oxides by reduct ion in carbon, for example i ron oxide is reduced in the

blast furnace to make iron.



Explain that iron is extracted in a blast furnace.

Consider and evaluate the social, economic andenvironmental impacts of exploiting metal ores, of using


EXT: Explain how electrolysis works and why it is not always used

1_2.1 and 2.2_extracting metals extracting iron

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