Extraction of Metals Flashcards
(21 cards)
What is an ore?
A rock which contains enough of a certain metal for it to be economically viable to extract
Why is Coke not always a suitable reducing agent?
At high temperatures reactive metals react with coke to form carbides, and sometimes the temperature required for reaction with carbon is so high it’s uneconomic
Which elements are metals most commonly combined with in ores?
Oxygen and Sulfur
What reducing agent is used to extract Tungsten?
Oxygen
How are sulfide ores converted to oxides?
Roasting
What is an advantage of using coke as a reducing agent?
It is cheaply obtained and abundant
Why is the temperature of a blast furnace hotter at the end of the reaction than at the start?
The reaction is exothermic
What reducing agent reacts with iron oxide inside a blast furnace?
Carbon monoxide
Why is coke used in a blast furnace?
To produce heat and to form carbon monoxide, which is a reducing agent that reacts with iron oxide
write the equation for the reduction of iron oxide by carbon monoxide
Fe2O3(s)+3CO(g) —> 2Fe(l) + 3CO2(g)
write the reaction for the roasting of Zinc Sulfide
ZnS(s) + 1.5O2(g) —>ZnO(s) + SO2(g)
Why can’t aluminium be extracted in a blast furnace?
it is more reactive than carbon
Why is molten cryolite used to dissolve aluminium?
It lowers the melting point of aluminium
Why must aluminium be molten for electrolysis to work?
So the ions are free to move to the electrode
What is the main cost of electrolysis?
Electricity
Write the half equation for the reaction that occurs at the negative electrode
2Al3+ + 6e- —–>2Al
What product is formed at the positive electrode during the electrolysis of aluminium?
Oxygen
Write the full equation for the decomposition of aluminium oxide
Al3O3 ——> 2Al + 1.5O2
What two processes are used to extract titanium
Conversion to titanium chloride and reduction
write the equation for the conversion of titanium oxide to titanium chloride
TiO2(s) + 2C(s) + 2CL2 —> TiCl4(l)+2CO(g)
write the equation for he reduction of titanium chloride by sodium
TiCl4(l) + 4Na(l) —> Ti(l) + 4NaCl(l)
