Chapter 3 - Metals And Their Uses

Question 1

How can metals be extracted from compounds

Answer 1

By displacement using a more reactive element.

Question 2

How can metals which are less reactive than carbon be extracted from their oxides

Answer 2

By heating them with carbon

Question 3

What kind of reaction is it if carbon is used to extract metals

Answer 3

Reduction reaction because carbon removed the oxygen from the oxide to produce the metal

Question 4

Why has cast iron only got a few uses

Answer 4

The impurities make it hard and brittle

Question 5

Why has pure iron (removing carbon dioxide and impurities) got a few uses

Answer 5

It’s too soft for many uses

Question 6

What are the properties of low carbon steels

Answer 6

They are easily shaped

Question 7

What are the properties of high carbon steels

Answer 7

They are hard

Question 8

What is a useful property of stainless steel

Answer 8

It resists corrosion

Question 9

What are some properties of aluminium

Answer 9

It has a low density and is resistant to corrosion

Question 10

How is aluminium extracted

Answer 10

By electrolysis of molten aluminium oxide because aluminium is more reactive than carbon so it’s oxide cannot be reduced using carbon.

Question 11

Why is aluminium expensive to extract

Answer 11

The process of electrolysis requires high temperatures and a lot of electricity.

Question 12

What are some properties of titanium

Answer 12

It’s resistant to corrosion and is very strong. It also has a low density compared with other strong metals

Question 13

How can titanium oxide be reduced by

Answer 13

Carbon but the metal reacts with carbon making it brittle

Question 14

How can copper be extracted from copper rich ores

Answer 14

By smelting. This means heating the ore strongly in a furnace

Question 15

What does smelting produce

Answer 15

Impure copper, which can be purified by electrolysis

Question 16

What are the two ways of extracting copper from low grade ores

Answer 16

• Phytomining- uses plants to absorb copper compounds from the ground. The plants are burned and produce ash from which copper can be extracted
• Bioleaching- uses bacteria to produce solutions containing copper compounds

Question 17

What properties make transition metals useful materials for making things

Answer 17

They are good conductors of heat and electricity. Many of them are strong but can be bent or hammered into shape

Question 18

What properties of copper make it useful for making pipes and tanks in water and heating systems.

Answer 18

It’s a very good conductor of heat and does not react with water. It can be bent but it is hard enough to keep its shape. It’s a very good conductor of electricity so it is used to electrical wiring

Question 19

What are the advantages of recycling

Answer 19

Recycling metals saves the energy needed to extract the metal. Recycling saves resources because less ore needs to be mined. Also less fossil fuels is needed to provide the energy to extract the metal from its ore

Question 20

What are the benefits of using metals in construction

Answer 20

• They are strong
• They can be bent into shape
• They can be made into flexible wires
• They are good electrical conductors

Question 21

What are the drawbacks of using metals in construction

Answer 21

• Obtaining metals from ores causes pollution and uses up limited resources
• Metals are more expensive than other materials such as concrete
• Iron and steel can rust

Question 22

What is an ore

Answer 22

Rock that contains enough of a metal to make it worth extracting the metal