REDUCTION OF METALS
9TH GRADE
Answer those questions:
• What is an ore ?
• Which metal is the most abundant on the Earth’s crust?
• Find the names of the ores where those metals could be
found: iron, aluminium, tin, copper, zinc, lead, silver,
titanium, sodium.
• Find the materials that could be used as reducing agents
for extracting metals from their ores?
• Which one is the most ecological one ? Why ?
ABUDANCE
OF METALS
The most abundant varieties in
the Earth’s crust are aluminum,
iron,
calcium,
sodium,
potassium, and magnesium.
The vast majority of
metals are found in ores
(mineral-bearing substances),
but a few such as copper, gold,
platinum, and silver frequently
occur in the free state because
they do not readily react with
other elements.
Fe2O3 + 3C  2Fe + 3CO
• Fe+3 + 3e- Fe0 |x2 reduction
• C0-2e- C+2 |x3
oxidation
Fe+3 oxidizing agent, C- reducing agent
reduction with carbon
ZnO + CO  Zn + CO2
• Zn+2 + 2e-  Zn0 |x2|x1 reduction
• C+2 – 2e-  C+4 |x2|x1 oxidation.
Zn+2 – oxidizing agent, C+2 - reducing agent
reduction with carbon (II) oxide
Cr2O3 + 3H2  2Cr + 3H2O
• Cr+3 + 3e- Cr0 |x2
reduction
• H2-2e- 2H+1 |x3
oxidation,
Cr+3 – oxidizing agent, H2 – reducing agent
reduction with hydrogen
3NiO + 2Al  3Ni + Al2O3
• Ni+2 + 2e-  Ni0 |x3 reduction
• Al0 - 3e- Al0 |x2
oxidation,
Ni+2 – oxidizing agent, Al0 – reducing agents
reduction with aluminum
2FeS + 3O2  2FeO + 2SO2
• S-2 - 6e-  S+4 |x4|x2
oxidation
• O2 + 4e-  2O-2 |x6|x3 reduction
S-2 – reducing agent, O-2 – oxidizing agent
combustion