SC11 - Obtaining and Using Metals ✓ Flashcards
SC11a - List the resctivity series [with a way to remember it]
- Pop Potassium
- Stars Sodium
- Can Calcium
- Make Magnesium
- Absolute Aluminium
- Crazy (Carbon)
- Zillions Zinc
- If Iron
- Tiny Tin
- Little Lead
- Children Copper
- Spend Silver
- Good Gold
- Pennies Platinum
SC11a - How do potassium, calcium and sodium react with water and dilute acids?
- Reacts with cold water to from hydrogen and metal hydroxide
- Reacts violently with acid
SC11a - How do magnesium, aluminium, zinc and iron react with water and dilute acids?
- Reacts very slowly if at all when with cold water
- But reacts with steam to form metal oxide and hydrogen
- Reacts with acid to form hydrogen and salt solution
SC11a - How do copper, silver, gold and platinum react with water and dilute acids?
They don’t as they are inert in their pure form.
SC11a - What is a displacement reaction?
- A reaction in which a more reactive element displaces a less reactive element from a compound.
- e.g. Zn + CuSO4 → ZnSO4 + Cu
SC11a - A displacement reaction is also another type of reaction. What is this and how can you show this?
A redox reaction as the charge on the metals switch around. e.g. in Zn + CuSO4 -> ZnSO4 + Cu the ionic euation shows that Zn + Cu2+ -> Zn2+ + Cu
SC11b - What are the three ways you can extract metals and how do these relate to their position on the reactivity series?
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Found uncombined in the earth’s crust.
- This applies to elements gold and lower in the reactivity series
-
Extacted by heating an ore with carbon.
- This is for elements less reactive than carbon or else carbon can’t displace it
-
Electrolysis of molten compound.
- This is very expensive so only used for aluminium and upwards as they cannot be ehated with carbon to be extracted
SC11b - What is an ore?
A rock that contains enough of a metal to extract it for a profit.
SC11b - What are the two biological methods of extraction?
-
Phytoextraction:
- Growing plants on lands that contain the desired matal so that they absorb it.
- These are then burned and the metal is obtained fromt their ashes
-
Bioleaching:
- Bacteria is grown on low-grade(uneconomical) ore.
- This forms a leachate (solution containing the desired metal compound)
- The copper is extracted by displacing it with scrap iron.
SC11b - What are the advantages and disadvantages of using bioleaching?
Pros:
- No harmful gases produced
- Less landscape damage than mining
- Conserves supplies of high grade ores
- Doesn’t require high temeratures
Cons:
- Very slow
- Toxic substances can be produced which damage the environment
SC11b - What are the advantages and disadvantages of using phytoextraction?
Pros:
- No harmful gases produced
- Less landscape damage than mining
- Conserves supplies of high grade ores
- Can extract minerals from contaminated soils
Cons:
- Very slow
- More expensive than mining some ores
- Plant growth is dependant on weather conditions
SC11c - What are oxidation, reduction and redox reactions in terms of oxygen?
- Oxidation is the gain of oxygen
- Reduction is the loss of oxygen
- A redox reaction is a reaction in which a substance is oxidised and another is reduced
SC11c - What is corrosion?
When a metal reacts with oxygen (oxidises) making it weaker over time
SC11c - How is rusting different to corrosion?
Rusting occurs when iron/steel reacts with oxygen and water.
SC11c - Why don’t some metals such as aluminium corrode very quickly, despite being very reactive?
They form a protective layer of tarnish stopping any further corrosion
