Metals

Question 1

physical properties of metals

Answer 1

• malleable and ductile
• sonorous
• lustrous
• high melting and boiling point
• good conductors of heat and electrcitiy

Question 2

chemical properties of metals

Answer 2

• react with dilute acids to produce salt and hydrogen

- react with oxygen to form metal oxides

Question 3

what are alloys

Answer 3

• contain different types of atoms that disrupt the orderly layer of atoms in the structure
• makes it difficult for the layers to slide over each other and makes alloys harder and stronger than pure metal

Question 4

how does calcium react with cold water

Answer 4

calcium reacts slowly with cold water even though it is reactive

Question 5

why doesn’t aluminum react with water or dilute acids

Answer 5

it reacts with oxygen to form a protective oxide layer that coats the metal and prevents it from further reacting with water or acids

Question 6

what is thermal decompostion

Answer 6

breakdown of compounds upon applying heat

Question 7

extraction of metals

Answer 7

• metals below carbon in the reactivity series can easily be extracted from their ores by reduction using carbon
• the more reactive metals, those above carbon, have to be extracted by electrolysis

Question 8

extraction of aluminium

Answer 8

extracted from its ore, bauxite, by electrolysis

Question 9

extraction of iron substances needed

Answer 9

• ore: haematite - iron (III) oxide
• raw materials: coke, haematite, limestone
• hot air is required to provide oxygen and to provide suffiient heat for reactions to take place in the furnace

Question 10

description of iron extraction

Answer 10

molten iron from the blast furnance is poured into an oxygen furnace. Basic calcium oxide is added, and a jet of oxygen is turned on. The calcium oxide neutralises the acidic impurities, forming slag that is skimmed off. The oxygen burns all the other impurities away

Question 11

blast furnance label diagram

Answer 11

https://ukcsma.co.uk/mpa-cms/wp-content/uploads/2016/08/csma-Blast-Furnace-Diagram.jpg

Question 12

iron extraction blast furnace reactions at each step

Answer 12

1. C + O2 -> CO2
2. CO2 + C -> 2CO
3. 3CO + Fe2O3 -> 3COs + 2Fe
4. molten iron flows to bottom
5. CaO react with acidici impurities to form slag

Question 13

zinc extraction

Answer 13

• ore: zinc blende, sinc sulphide
• ore is first treated by a process called toasting in which the ore is burned in oxygen to produce zinc oxide and sulphur dioxide

Question 14

zinc extraction reactions

Answer 14

2ZnS + 3O2 -> 2ZnO + 2SO2

ZnO + CO -> Zn + CO2

Question 15

advantages of recycling

Answer 15

• profitable, material can be resold
• reduces waste, landfill space is running out
• reduces landfill
• saves energy - avoids the procedure of extraction again
• uses for fewer resources (less coal and iron

Question 16

disadvantages of recycling

Answer 16

• often different mixtures of many metals, sorting this out can become pricey
• purifying is expensive and uses more electricity than electrolysis requires
• people rather not recycle

Question 17

uses of aluminium

Answer 17

• in the manufacture of aircraft because of its strength and low density
• in food containers because of its resistance to corrosion

Question 18

uses of copper

Answer 18

• electrical wiring, good conductors of electricity

- cooking utensils - good conductors of heat

Question 19

different types of steel

Answer 19

• mild steel : used for car bodies and machinery, harder and stronger than pure iron due to the presence of other metals and elements
• stainless steel: used in chemical plants and cutlery, hard and strong resistant to corrosion due to presence of other metals such as nickel and chromium

Question 20

uses of zinc

Answer 20

• galvanising steel
• used to make brass (alloy)
• used in car batteries