SC5iii - EXTRACTION OF METALS

Question 1

general equation for reaction of metals with water

Answer 1

metal + water -> metal hydroxide + hydrogen

Question 2

reactivity series

Answer 2

Potassium
Sodium
Calcium
Magnesium
Aluminium
Zinc
Iron
Tin
Lead
Copper
Silver
Gold

Question 3

describe what happens in a displacement reaction

Answer 3

a more reactive metal ‘steals’ the non-metal from a less reactive metal compound
-> the more reactive metal DISPLACES the less reactive metal

Question 4

displacement reactions are _____ reactions

Answer 4

REDOX
REDuction and OXidation

Question 5

describe what happens in a REDOX reaction

Answer 5

something is REDuced by gaining electrons
something is OXidised by losing electrons

Question 6

metals that must be extracted from their ores by electrolysis

Answer 6

metals MORE reactive than carbon
potassium
sodium
calcium
magnesium
aluminium

Question 7

metals that can be extracted from their ores by heating with carbon

Answer 7

metals LESS reactive than carbon
zinc
iron
tin
lead

Question 8

metals that are found naturally as the metal

Answer 8

UNREACTIVE metals
copper
silver
gold
platinum

Question 9

describe how metals are extracted by heating with carbon

Answer 9

• the metal ores (metal oxides) are heating with carbon
• the carbon can act like a metal and ‘steal’ the oxygen to make carbon dioxide
  eg. iron oxide + carbon -> iron + carbon dioxide
  2FeO + C -> 2Fe + CO2
• this can ONLY be used for metals that are LESS reactive from carbon

Question 10

describe what happens in corrosion

Answer 10

in corrosion metals gain oxygen to give the metal oxide
metals are therefore oxidised
more reactive metals gain oxygen more easily and corrode easily

Question 11

why should metals be recycled at the end of their use?

Answer 11

this uses less metal ores which can be in short supply and require a lot of energy and cause environmental problems to extract

Question 12

what is a life cycle assessment?

Answer 12

an assessment considering how environmentally sustainable a product is
this looks at all the stages in a products life and evaluates the impact of each on the environment

Question 13

stages of a life cycle assessment (4)

Answer 13

1. obtaining and processing raw material
2. manufacturing the product
3. using the product
4. disposal