Extraction Flashcards

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1
Q

Why heat a mixture of aluminium oxide and carbon doesn’t produce aluminium

A

as aluminium more reactive than carbon

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2
Q

Explain how Al metal forms at negative electrode

A

Al positive ion attracted to negative electrode where they gain electrons from alumnium atom

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3
Q

Why cryloite used in electrolysis of alumnium oxide

A

Good solvent for bauxite
Its a fusing material lower temperature of process

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4
Q

State one major cost involved in extraction of aluminium but not in extraction of iron

A

Electricity

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5
Q

Explain why obtaining molten alumnium oxide is difficult

A

Need lots of energy

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6
Q

Explain why positive electrodes need to replaced regulary

A

As graphite electrode react with oxygen at anode form carbon dioxide and carbon monoxide

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7
Q

Describe structure of alumnium metal

A

Giant metallic lattice,layer of positive ions with decolaised free moving electrons

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8
Q

Explain why Al is good conductor of electricity

A

As it has decolaised free moving electrons

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9
Q

Name process used to extract al

A

Electrolysis

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10
Q

Explain why aluminium oxide is dissolved in molten cryolite

A

As aluminium oxide has high melting point but solution has lower m.p

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11
Q

Suggest how titanium could be obtained from Ireland of rutile and explain

A

By electrolysis as titanium more reactive than iron

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12
Q

Name of iron ore Fe2O3

A

Hematite

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13
Q

What is the gas that makes up the highest percenatge of waste gases

A

Nitrogen

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14
Q

Explain how carbon monoxide is formed in blast furnace

A

Carbon react with oxygen to form carbondioxide then carbon dioxide react with carbon(coke) form carbon monoxide gas

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15
Q

What is galvanising

A

Coating with a layer of zinc to prevent rusting

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16
Q

Explain how galvanizing continue to protective iron when layer of zinc is damaged

A

Zn more reactive than iron so zinc oxidised readily by losing electrons protect iron from rusting

17
Q

Limestone

A

Calcium carbonate

18
Q

Chemical name for rust

A

Hydrated iron(iii)oxide

19
Q

Why neon not react with iron wool

A

Don’t lose or share or gain electrons

20
Q

Why percentage of air calculated from student’s results less than 21%?

A

Iron wool not enough to react

21
Q

Why paint prevent iron in car bodied from rusting

A

As paint act as barrier

22
Q

What is meant by exothermic

A

Reaction produce heat

23
Q

Why iron produced in the thermite reaction is molten

A

As reaction is exothermic, produce heat energy more than melting point at diamond