chapter 20 lecture 1 Flashcards
chlorides
group 1
carbonates
group 2
phosphates
group 3
oxides
left side of transition metals and aluminum
sulfides
right hand side of transition metals
native metals
some of the bottom of periodic table
what are the methods for production of metals from their ores?
-electrolysis
-reaction with another metal (usually a more reactive metal)
-reaction with H2 (producing water)
-reaction with C/CO (producing CO2)
Na from NaCL
-Na+ e- –> Na(l) - reduction (cathode)
- 2Cl - —-> Cl2(g) + 2e- —- oxidation (anode)
sodium is very reactive so this takes place in an oxygen free environment
production of K from KCl
-elemental sodium mixed with molten KCl
- K is more reactive than sodium
- equilibrium would lie towards the reactants
- K forms a gas, boils away, and is removed forcing reaction to the right
dow process for magnesium
set up plant near ocean
-bring sea water into take
-make that liquid basic
-react magnesium with OH to make Mg(OH)2
-CaCO3 (sea shell or limestone)
-CaCO3 —-> CaO + C)2
-
aluminum from bauxite ore
-ore contains Al2O3 and Fe2O3 as an impurity which must be removed
-ore is crushed and dissolved in water
-solution made basic forming Fe(OH)3 (s) and Al(OH)4 (aq), the aluminum is staying in solution as complex ion while iron ppts out
-iron ppt is filtered out
-CO2 bubbled through solution lowering hydroxide concentration and allows aluminum to ppt
-Al(OH)3 is heated which reforms pure Al2O3
when aluminum is purified, what do we do with it?
electrolysis
Hall/Heroult process
cryolite - which melts at 1000ºC
carbon at anode & cathode
aluminum reduced at cathode
anode producing carbon dioxide
what is produced from a blast furnace?
iron
what is iron ore mostly?
Fe2O3
reagents in blast furnace
ore Fe2O3 and SiO2 (sand)
coke - C
limestone - CaCO3
air/O2
what are the reactions that take place in blast furnace
2Cn(s) + O2(g) –> 2CO(s)
Fe2O3(s) + 3CO(g) __> 2Fe(l) + 3CO2(g)
CaCO3(s) –> CaO(s) + CO2(g)
CaO(s) + SiO2(s) –> CaSiO3(l)
slag formula
CaSiO3 (l)
what is slag used for
concrete, road beds
pig iron
full of impurities such as carbon
-purified by mixing with scrap iron and more limestone and reacted at high temps in pure oxygen
-carbon is tuned to carbon dioxide and other impurites in slag
-different types of steel can be produced by introducing other metals into the iron
-200 metric tons of steel can be produced in a single blow
how are metal sulfides heated
in the presence of air/oxygen
more reactive metals form what
metal oxide product
less reactive metals such as what
copper and mercury form pure metal
current gold mining methods
chemically with cyanide and oxygen - oxygen is oxidizing agent and cyanide forms complex ion, react this with zinc and we get solid gold
