C10 - Metals

Question 1

Describe metallic bonding [2]

Answer 1

Lattice of positive metal ions in a sea of delocalised electrons

Question 2

Describe general physical properties of metals [4]

Answer 2

High melting and boiling points, malleable, ductile, good conductors of heat and electricity

Question 3

Define malleable [1]

Answer 3

Can be bent of hammered into shape

Question 4

Define ductile [1]

Answer 4

Can be drawn into wires

Question 5

Define an alloy [1]

Answer 5

A mixture of a metal with another substance

Question 6

Explain why an alloy is more useful than the pure metal [3]

Answer 6

It is harder (more difficult to scratch) because the other element disrupts the lattice structure and makes it more difficult to remove the layers from the metal

Question 7

What is brass [1]

Answer 7

An alloy of copper and zinc

Question 8

What do we call an alloy that contains iron and other substances? [1]

Answer 8

Steel

Question 9

Why is nickel and chromium alloyed with iron? [2]

Answer 9

Chromium prevents steel from rusting, nickel makes it harder

Question 10

Place in order of reactivity the following elements: Al, C, Ca, Cu, Fe, H₂, K, Mg, Na, Zn [1]

Answer 10

K, Na, Ca, Mg, Al, C, Zn, Fe, H₂, Cu

Question 11

How does the reactivity of a metal relate to how easy it is to extract from its ore? [1]

Answer 11

The more reactive a metal is the more difficult it is to extract from its ore

Question 12

How does the reactivity of a metal relate to its tendency to form a positive ion? [1]

Answer 12

The more reactive a metal the easier it is to lose its valence electron(s) and form a positive ion

Question 13

Write a symbol equation for the reaction between magnesium and hydrochloric acid [1]

Answer 13

Mg (s) + 2HCl (aq) → MgCl₂ (aq) + H₂ (g)

Question 14

Write a symbol equation for the reaction between magnesium and oxygen [1]

Answer 14

2Mg (s) + O₂ (g) → MgO (s)

Question 15

Write a symbol equation for the reaction between sodium and cold water [1]

Answer 15

2Na (s) + 2H₂O (l) → 2NaOH (aq) + H₂O (g)

Question 16

Write a symbol equation for the reaction between magnesium and steam [1]

Answer 16

Mg (s) + 2H₂O (g) → MgO (s) + H₂ (g)

Question 17

Define an ore [1]

Answer 17

A rock that contains a high enough percentage of metal for economic extraction

Question 18

Why is it important that metals are recycled?

Answer 18

Because metal ores are finite

Question 19

How are elements above carbon in the reactivity series extracted from their ores? [1]

Answer 19

Electrolysis

Question 20

How is iron extracted from the metal ore haematite in the blast furnace [1]

Answer 20

By heating with carbon

Question 21

Write 3 symbol equations to show how carbon is used to extract iron from haematite [3]

Answer 21

C + O₂ → CO₂ C + CO₂ → 2CO Fe₂O₃ + 3CO → 2Fe + 3CO₂

Question 22

Explain whith the use of 2 symbol equations why limestone (CaCO₃) is used in the blast furnace [3]

Answer 22

To remove acidic impurities such as silicon (IV) oxide CaCO₃ → CaO + CO₂ CaO + SiO₂ → CaSiO₃

Question 23

Explain 2 uses of aluminium [4]

Answer 23

Aircraft because of its strength and low density and in food containers because of its resistance to corrosion

Question 24

Describe the uses of mild steel and stainless steel [2]

Answer 24

Mild steel for car bodies and machinery and stainless steel for chemical plants and cutlery

Question 25

Describe and explain the apparent unreactivity of aluminium [2]

Answer 25

Aluminium forms an oxide layer which protects the metal underneath

Question 26

Explain why zinc is used for galvanising steel [2]

Answer 26

As a more reactive metal zinc provides sacrificial protection, this means is reacts before the metal underneath