Metals Flashcards
Describe how metals occur naturally
Combined with other elements in compounds called ores
Name the ore in which aluminium occurs naturally, also state the chemical formula for the ore
Bauxite
Al2O3
Name the ore in which zinc occurs naturally, also state the chemical formula for the ore
Zinc blende
ZnO
Name the ore in which uranium occurs naturally, also state the chemical formula for the ore
Pitch blende
UO (uranium oxide)
Name the ore in which iron occurs naturally, also state the chemical formula for the ore
Haematite
Fe2O3
Name the ore in which tin occurs naturally, also state the chemical formula for the ore
Casserite
Sn02
Name the ore in which copper occurs naturally, also state the chemical formula for the ore
Copper pyrites
Cu2S
Name the ore in which gold occurs naturally, also state the chemical formula for the ore
Gold occurs naturally pure, with the chemical formual Au
State four uses of aluminium
- Pans and food containers, utensils
- Overhead electricity cables
- Aircraft parts
- As an alloy when mixed with copper
Describe why aluminium is a suitable metal for the manufacturing of aircraft parts
Light weight metal and does not corrode
State three uses of copper
- Electrical wiring
- In water pipes
- Alloys
Name the two metals present in duralium
Copper, aluminium
Name the two metals present in brass
Copper, zinc
Name the two metals present in bronze
Copper, tin
State why copper is a suitable metal for using in water pipes
Copper is unreactive and does not corrode easily
State two uses of zinc
- Galvanising
- Alloys (brass)
Name a use of iron, and state why iron is suitable for this use
Structural material, strong and malleable
Name one use of tin, and state why tin is suitable for this use
Coating steel cans, unreactive and non-toxic
Fully describe the extraction process of aluminium
Aluminium is a reactive metal and needs to undergo electrolysis to be extracted. During electrolysis, bauxite is dissolved in molten cryolite, forming the electrolyte. Carbon or graphite plates act as the anode, also as the cathode, at which molten aluminium accumilates. Aluminium ore is dissolved in croylite in order to lower the melting point of the ore. Oxygen bubbles to the top. (Probeer maar self sin maak hiervan..)
Name the substances that is contained within the charge of a blast furnace
- Haematite
- Coke (Pure carbon)
- Limestone
Describe the 6 reactions that take place during the extraction of iron in a blast furnace
1. The coke burns C + 02 = C02 2. Coke reduces carbon dioxide C02 + C = 2C0 3. Carbon monoxide reduces iron ore Fe2O3 + 3C0 = 2Fe + 3CO2 4. Carbon reduces iron ore 2Fe203 + 3C = 4Fe + 3CO2 5. Limestone decomposes CaCO3 = CaO + CO2 6. Slag forms CaO + SiO2 (sand) = CaSiO3
Name one use for slag
Road building
Describe the extration of copper
The ore is roasted in air
Describe the extraction of sodium
Electrolysis of molten sodium chloride
Describe the extraction of zinc
Roasting in air
Describe the term “alloy”
A mixture of metals, often to change the properties of metals and make them more usefull
Describe two ways in which rusting or iron can be prevented
- Galvanising (covering with a zinc layer)
- Painting
