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
(Carbon)
Zillions Zinc
If Iron
Tiny Tin
Little Lead
Children Copper
Spend Silver
Good Gold
Pennies PlatinumSC11a - 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?
- 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 id 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 landsthta 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?
\+ No harmful gases produced \+ Less landscape damage than mining \+ conserves supplies of high grade ores \+ Doesn't require high temeratures - Very slow - Toxic substances can be produced which damage the environment
SC11b - What are the advantages and disadvantages of using phytoextraction?
+ No harmful gases produced
+ Less landscape damage than mining
+ conserves supplies of high grade ores
+ Can extract minerals from contaminated soils
- Very slow
- More expensive than mining soem 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 reacts ith 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
