Extraction Flashcards
Why heat a mixture of aluminium oxide and carbon doesn’t produce aluminium
as aluminium more reactive than carbon
Explain how Al metal forms at negative electrode
Al positive ion attracted to negative electrode where they gain electrons from alumnium atom
Why cryloite used in electrolysis of alumnium oxide
Good solvent for bauxite
Its a fusing material lower temperature of process
State one major cost involved in extraction of aluminium but not in extraction of iron
Electricity
Explain why obtaining molten alumnium oxide is difficult
Need lots of energy
Explain why positive electrodes need to replaced regulary
As graphite electrode react with oxygen at anode form carbon dioxide and carbon monoxide
Describe structure of alumnium metal
Giant metallic lattice,layer of positive ions with decolaised free moving electrons
Explain why Al is good conductor of electricity
As it has decolaised free moving electrons
Name process used to extract al
Electrolysis
Explain why aluminium oxide is dissolved in molten cryolite
As aluminium oxide has high melting point but solution has lower m.p
Suggest how titanium could be obtained from Ireland of rutile and explain
By electrolysis as titanium more reactive than iron
Name of iron ore Fe2O3
Hematite
What is the gas that makes up the highest percenatge of waste gases
Nitrogen
Explain how carbon monoxide is formed in blast furnace
Carbon react with oxygen to form carbondioxide then carbon dioxide react with carbon(coke) form carbon monoxide gas
What is galvanising
Coating with a layer of zinc to prevent rusting
Explain how galvanizing continue to protective iron when layer of zinc is damaged
Zn more reactive than iron so zinc oxidised readily by losing electrons protect iron from rusting
Limestone
Calcium carbonate
Chemical name for rust
Hydrated iron(iii)oxide
Why neon not react with iron wool
Don’t lose or share or gain electrons
Why percentage of air calculated from student’s results less than 21%?
Iron wool not enough to react
Why paint prevent iron in car bodied from rusting
As paint act as barrier
What is meant by exothermic
Reaction produce heat
Why iron produced in the thermite reaction is molten
As reaction is exothermic, produce heat energy more than melting point at diamond
