SC11 - Obtaining and Using Metals ✓ Flashcards
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
SC11a - How do calcium, magnesium, alumnium, zinc and iron react with dilute acid?
They react to form a salt solution + hydrogen
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 - How do magnesium, aluminium, zinc and iron react with water?
- They react very slowly with cold water but react with steam to form a metal oxide and hydrogen
SC11a - List the reactivity series [with a way to remember it]
- Please Potassium
- Stop Sodium
- Calling Calcium
- Me Magnesium
- AAluminium
- Careless (Carbon)
- Zebra Zinc
- Instead Iron
- Try Tin
- Learning Lead
- How Hydrogen
- Copper Copper
- Saves Silver
- Gold Gold
SC11a - What 2 metals react violently with dilute acid?
- Potassium
- Sodium
SC11a - What 3 metals react with cold water to form hydrogen and metal hydroxide?
- Potassium
- Sodium
- Calcium
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 - What is the link between reactivity and a metal’s tendency to form cations?
- The more react they are, the higher their ability to form positive ions
SC11b - How do we extract metals that are:
- Less reactive than carbon
- More reactive than carbon
- Very unreactive elements (less reactive than copper)
- Less reactive than carbon - heat an ore with carbon (displacement reaction)
- More reactive than carbon - electrolysis of molten compound
- Very unreactive elements (less reactive than copper) - they are found in their native state as an uncombined element
SC11b - What are the advantages and disadvantages of Bioleaching?
Pros:
- doesn’t need high temperatures
Cons:
- toxic substances can be produced by the process and damage the environment
SC11b - What are the advantages and disadvantages of both bioleaching and phyto extraction?
Pros:
- No harmful gases produced
- Less landscape damage than mining
- Conserves supplies of high grade ores
Cons:
- Very slow
SC11b - What are the advantages and disadvantages of using phytoextraction?
Pros:
- Can extract minerals from contaminated soils
Cons:
- More expensive than mining some ores
- Plant growth is dependant on weather conditions
SC11b - What are the three ways you can extract metals and how do these relate to their position on the reactivity series?
-
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 - Describe 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.
