Inorganic Chemistry - Extraction and Uses of Metals (Paper 2)

Question 1

where are most metals found in the earth’s crust?

Answer 1

most metals are found combined with other elements, in rocks called ore

Question 2

where are unreactive metals found in the earth’s crust?

Answer 2

they’re found as the uncombined element

Question 3

what does extracting a metal from its ore involve?

Answer 3

• removing oxygen from metal oxides
• if the ore contains a metal below carbon in the reactivity series then the metal is extracted by reaction with carbon in a displacement reaction
• if the ore contains a metal above carbon in the reactivity series then electrolysis is used to extract the metal

Question 4

what are the uses of aluminium?

Answer 4

• aircrafts and cans (low density/resists corrosion)
• power cables (conducts electricity/ductile)
• pots and pans (low density/strong (when alloyed)/good conductor of electricity and heat)

Question 5

why does aluminium resist corrosion?

Answer 5

it has a very thin, but very strong, layer of aluminium oxide on the surface.

Question 6

what are the uses of copper

Answer 6

• electrical wires (very good conductor of electricity/ductile)
• pots and pans (very good conductor of heat/unreactive/malleable)
• water pipes (unreactive/malleable)
• surfaces in hospitals (antimicrobial properties/malleable)

Question 7

what are the uses of iron?

Answer 7

• buildings (strong)
• saucepans (conducts heat/high melting point/malleable)

Question 8

what are the 3 main types of steel?

Answer 8

1. mild steel (iron plus up to 0.25% carbon) - strong material, malleable, rusts easily
2. high-carbon steel (iron plus 0.6-1.2% carbon) - harder than mild steel but not as malleable
3. stainless steel (iron with chromium and nickel) - resistant to corrosion as it forms a strong oxide layer

Question 9

what are uses of mild steel?

Answer 9

nails, car bodies, shipbuilding, girders

Question 10

what are uses of high-carbon steel?

Answer 10

cutting tools, masonry nails

Question 11

what are uses of stainless steel?

Answer 11

cutlery, cooking utensils, kitchen sinks

Question 12

what is an alloy?

Answer 12

a mixture of a metal and one or more elements, usually other metals or carbon

Question 13

why are alloys harder than pure metals?

Answer 13

In an alloy, the different elements have slightly different-sized atoms. This breaks up the regular lattice arrangement and makes it more difficult for layers of ions to slide over each other