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

Question 3

Define malleable [1]

Answer 3

• Can be bent or malleable 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 and another substance

Question 6

Explain why an alloy is more useful than a 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 layers from the
  metal

Question 7

What is brass [1]

Answer 7

• An alloy of copper and zink

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 steel 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 reactivity of a metal relate to its tendency to form a positive ion? [1]

Answer 12

• The more reactive a metal is the easier it is to lose valance electron(s) and form positive ions.

Question 13

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

Answer 13

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

Question 14

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

Answer 14

• 2Mg (s) + O₂ (g) → MgO (s)

Question 15

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

Answer 15

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

Question 16

Write an 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? [1]

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 with 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
• 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
• 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,
  + it reacts before the metal underneath