Unit 1: 3 - Metals and their uses

Question 1

What is an ore?

Answer 1

Rock that contains enough metal or a metal compound to make it worth extracting.

Question 2

What type of metals can be extracted from ores using physical methods (e.g. smelting)?

Answer 2

Unreactive metals (low in the reactivity series, such as gold) as they are found as the pure metal rather than as a compound.

Question 3

How can metals be extracted from a compound?

Answer 3

By displacement using a more reactive element.

Question 4

What type of elements can be extracted by heating with carbon? What is this called?

Answer 4

Metals which are less reactive that carbon; this is called reduction.

Question 5

How is iron (III) oxide extracted from an ore?

Answer 5

In a blast furnace using carbon.

Question 6

How do reduction reactions work?

Answer 6

The carbon removes the oxygen which is released as carbon oxides (usually CO2).

Question 7

What percentage of iron is in the iron made from a blast furnace?

Answer 7

About 96%

Question 8

What is wrong with the iron made from a blast furnace?

Answer 8

The impurities make it brittle so it has few uses.

Question 9

Give a use for iron from a blast furnace.

Answer 9

Cast iron.

Question 10

What are steels?

Answer 10

Alloys of iron and other elements, often carbon or metals like chromium.

Question 11

What main property do low-carbon steels have?

Answer 11

They are easily shaped.

Question 12

What main property do high-carbon steels have?

Answer 12

They are hard.

Question 13

What is stainless steel?

Answer 13

Steel that contains larger quantities of other metals, like chromium, which resists corrosion.

Question 14

Why can aluminium not be reduced using carbon?

Answer 14

Aluminium is more reactive than carbon.

Question 15

What properties does aluminium have? (2)

Answer 15

Low density and resistant to corrosion (even though it is quite high up in the reactivity series).

Question 16

How is aluminium extracted?

Answer 16

Using electrolysis.

Question 17

What is aluminium usually made up into and why?

Answer 17

Alloys, as pure aluminium is not very strong.

Question 18

What properties does titanium have? (3)

Answer 18

It is very strong, resistant to corrosion and has a low density compared to other strong metals.

Question 19

What is the problem with extracting titanium from its oxide by reduction?

Answer 19

The metal reacts with the carbon making it brittle.

Question 20

Why is the extraction of titanium expensive?

Answer 20

It requires several stages and large amounts of energy.

Question 21

How can copper be extracted from copper-rich ores?

Answer 21

Smelting (physical method, as copper is quite unreactive).

Question 22

What is the problem with producing copper by physical methods and how do we deal with this?

Answer 22

It produces impure copper, which we then electrolyse.

Question 23

Why is smelting and purifying copper ore a problem?

Answer 23

It requires large amounts of energy.

Question 24

What is an increasing problem with copper?

Answer 24

It is a limited and very useful resource, and the amount of copper-rich ores are running out.

Question 25

Explain phytomining.

Answer 25

Plants that can absorb lots of minerals from the ground are grown on copper rich sites, and absorb the copper. These are then burnt for energy and the copper is extracted from the ash.

Question 26

Explain bioleaching.

Answer 26

Bacteria produce solutions containing copper compounds.

Question 27

How can solutions of copper compounds be displaced to give us pure copper?

Answer 27

By reacting them with a more reactive metal (like scrap iron).

Question 28

What do transition metals have in common?

Answer 28

Similar properties: Good conductors of heat and electricity; they can be bent or hammered into shape; they are useful for buildings, vehicles, containers, pipes and wires.

Question 29

Give 2 environmental issues with mining.

Answer 29

It involves digging up and processing large amounts of rock, which affects large areas of the environment. This produces large amounts of waste material.

Question 30

Why is recycling good? (2)

Answer 30

It saves energy needed to extract an ore, and less ore needs to be mined.

Question 31

Give at least 3 advantages for using metals in construction.

Answer 31

Any 3 from…

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

Question 32

Give 3 disadvantages for using metals in construction.

Answer 32

• Obtaining metals from ores causes pollution and uses up limited resources;
• Metals are more expensive than other materials (like concrete);
• Iron and steel can rust.