Using Materials

Question 1

What is rust?

Answer 1

Rust is the hydrated iron(III) oxide that forms on iron when it corrodes.

Question 2

Give two conditions needed for rusting of iron to occur.

Answer 2

Two conditions needed for rusting of iron to occur are water and oxygen.

Question 2

Which element does rusting specifically refer to?

Answer 2

Rusting specifically refer to the corrosion of iron.

Question 3

Write the word equation for the corrosion of iron.

Answer 3

The word equation for the rusting of iron is:

iron + water + oxygen ⟶ hydrated iron(III)oxide

Question 4

Give two examples of barrier methods that can prevent rusting.

Answer 4

Painting

Greasing

Electroplating

Question 5

True or False?

Rusting weakens the structure and integrity of iron over time

Answer 5

True.

Rusting weakens the structure and integrity of iron over time as more iron is lost.

Question 6

True or false?

Galvanising is the method of coating iron with a layer of lead.

Answer 6

False.

Galvanising is the method of coating iron with a layer of zinc.

Question 7

What is meant by sacrificial protection?

Answer 7

Sacrificial protection is when a more reactive metal is intentionally allowed to corrode to protect the metal it is covering.

Question 8

Why is zinc used to protect iron from corrosion?

Answer 8

Zinc is used to protect iron from corrosion because it is more reactive than iron so will react more readily with oxygen.

Question 9

What is an alloy?

Answer 9

An alloy is a mixture of metals, where the metals are mixed together physically but are not chemically combined.

Question 10

True or false?

A metal less reactive than iron can be used for galvanising.

Answer 10

False.

A metal more reactive than iron can be used for galvanising.

Question 11

Explain why low carbon steel can be used to make car bodies.

Answer 11

Low carbon steel can be used to make car bodies because it is soft and malleable.

Question 11

True or False?

Alloys are chemically combined mixtures of metals.

Answer 11

False.

Alloys are physical mixtures of metals, where the metals are not chemically combined.

Question 11

Describe the structure of an alloy.

Answer 11

Alloys contain atoms of different sizes which distort the regular arrangement of atoms.

Question 12

True or False?

Alloys can be made from metals mixed with non-metals.

Answer 12

True.

Alloys can also be made from metals mixed with non-metals such as carbon.

Question 13

How do properties of alloys differ from pure metals?

Answer 13

Alloys often have greater strength / hardness, or resistance to corrosion / extreme temperatures compared to pure metals.

Question 13

What is the cause of increased hardness and strength in alloys?

Answer 13

The increased hardness and strength of an alloy is caused by the different size atoms which distort the regular arrangements of atoms, preventing the layers from sliding over each other easily.

Question 14

State an advantage of using alloys over pure metals.

Answer 14

Greater strength

Greater hardness

Increased resistance to corrosion

Increased resistance to extreme temperatures

Question 15

Give one use of stainless steel.

Answer 15

Cutlery

Sinks

Chemical plants

Question 15

True or false?

Brass is an alloy of copper and tin.

Answer 15

False.

Brass is an alloy of copper and zinc.

Question 16

Name the two main elements in steel alloys.

Answer 16

The two main elements in steel alloys are iron and carbon.

Question 17

Name the two metals that bronze is an alloy of.

Answer 17

Bronze is an alloy of copper and tin.

Question 18

Why is high carbon steel used in cutting tools?

Answer 18

High carbon steel is used to make cutting tools because it is very hard.

Question 18

Why do thermosetting polymers have high melting points?

Answer 18

Thermosetting polymers have high melting points because there are strong cross-links between polymer chains that need lots of energy to overcome.

Question 19

True or false? Carats are used to express the purity of gold jewellery.

Answer 19

True. Carats are used to express the purity of gold jewellery.

Question 19

Why is pure gold not used to make jewellery?

Answer 19

Pure gold is not used to make jewellery because it is too soft.

Question 20

Name the monomer used to produce high density and low density poly(ethene).

Answer 20

The monomer used to produce high density and low density poly(ethene) is ethene.

Question 21

Why do high density and low density poly(ethene) have different properties?

Answer 21

High density and low density poly(ethene) have different properties because they are made under different conditions.

Question 22

The properties of a polymer depend on which two factors?

Answer 22

The monomers they are made from The conditions under which they are made

Question 23

Describe the structure of a thermosoftening polymer.

Answer 23

A thermosoftening polymer consists of individual, tangled chains with no cross-links between them.

Question 24

True or False? Thermosoftening polymers can be melted and remoulded to form different shapes.

Answer 24

True. Thermosoftening polymers can be melted and remoulded to form different shapes.

Question 25

Name the two components of a composite.

Answer 25

Two components of a composite are: Reinforcement Matrix

Question 26

Name the reinforcement and matrix used to make concrete.

Answer 26

Reinforcement: Aggregate (sand and gravel) Matrix: Cement

Question 26

True or False? In a composite, the matrix is surrounded by a reinforcement.

Answer 26

False. In a composite, the reinforcement is surrounded by a matrix.

Question 27

True or False? The matrix in carbon fibres is a polymer.

Answer 27

True. The matrix in carbon fibres is a polymer.

Question 28

True or False? Wood is a natural composite.

Answer 28

True. Wood is a natural composite.

Question 29

Give two examples of composites.

Answer 29

Concrete Fibreglass Carbon fibre Wood

Question 30

How is soda-lime glass made?

Answer 30

Soda-lime glass is made by heating a mixture of sand, sodium carbonate and limestone.

Question 31

True or False? Borosilicate glass has a lower melting point than soda-lime glass.

Answer 31

False. Borosilicate glass has a higher melting point than soda-lime glass.

Question 32

Describe how clay ceramics, such as bricks, are made.

Answer 32

Clay ceramics are made by shaping / moulding wet clay and then heating them in a furnace.