Save
Chem
Chapter 16 - Metal Extraction
Save
Share
Learn
Content
Leaderboard
Share
Learn
Created by
Merry Rasei
Visit profile
Cards (22)
Metals can be extracted from their
ores
View source
Electrolysis
1.
Expensive
2. Too much
energy
needed
View source
Reducing with cabon
1. Removal of
Oxygen
from metal
2. Less
expensive
3. Not
pure
View source
Metals extracted by electrolysis
K
Na
Ca
Mg
Al
View source
Hall- Héroult
process
Al
extraction
View source
ore=
bauxite
(Al2o3)
View source
Metals extracted by
reduction
with
carbon
In
Fe
Sn
Pb
Cu
Ag
Au
Pt
View source
Electrolysis/Reduction with carbon
1.
Impurities
are removed by
roasting
+ (NaOH) base
2.
Filtering
View source
Bauxite
(mp)
2000°C
View source
Reducing with carbon
1. Add
molten
cryolite
2. To reduce
melting
point
3. To increase
electrical conductivity
4. As a
solvent
View source
In iron extraction, Gases produced during the extraction: CO, CO2, N2
View source
Anode
has to be
replaced
regularly
View source
In Al extraction, O2 is produced at the anode, reacts with carbon anode, CO2 is produced
View source
Iron extraction
1.
Limestone
,
coke
, hematite
2. Waste gas:
CO
,
CO2
, N2
3.
Molten slag
4.
Molten iron
View source
Major impurities:
SiO2
(
acidic oxide
)
View source
pH
=
-log
[H+]
View source
Stainless steel
:
Fe
, Ni, Cr
View source
Metals with different reactivities
Produce electricity due to
chemical reaction
View source
The longer the reactivity difference between metals, the
higher
the voltage
View source
Hydrogen-Oxygen fuel cell
1.
H2
at anode,
O2
at cathode
2.
PEM
(Proton exchange membrane)
3. 2H2 +
O2
->
2H2O
View source
Advantages of
hydrogen
fuel
More
efficient
No need to recharge
Produce a large amount of
energy
Water
is the only product, no
CO2
emission, no pollution
View source
Disadvantages of H2 fuel
Difficult
to produce, store, transport
Explosive
Expensive
View source