2.4 Reactivity Series

Question 1

How much does potassium react with water?

Answer 1

Reacts violently

Question 2

How much does sodium react with water?

Answer 2

Reacts quickly

Question 3

How much does calcium react with water?

Answer 3

Reacts less strongly

Question 4

Calcium + Water word equation?

Answer 4

calcium + water ⟶ calcium hydroxide + hydrogen

Question 5

Calcium + Water chemical equation?

Answer 5

Ca(s) + 2H₂O(l) ⟶ Ca(OH)₂(aq) + H₂(g)

Question 6

Which metals react with dilute acids?

Answer 6

Metals above hydrogen in the reactivity series.

Question 7

General equation for metal + acid?

Answer 7

metal + acid ⟶ salt + hydrogen

Question 8

Magnesium + sulfuric acid chemical equation?

Answer 8

Mg + H₂SO₄ ⟶ MgSO₄ + H₂

Question 9

Magnesium + Hydrochloric Acid chemical equation?

Answer 9

Mg + 2HCl ⟶ MgCl₂ + H₂

Question 10

What happens during a metal displacement reaction?

Answer 10

A more reactive metal will displace a less reactive metal from its compounds

Question 11

Simple reactivity series? (With Mnemonic)

Answer 11

Potassium - Please
Sodium - Send
Lithium - Lions
Calcium - Cats
Magnesium - Monkeys
Aluminium - And
Carbon - Cute
Zinc - Zebras
Iron - Into
Hydrogen - Hot
Copper - Countries
Silver - Signed
Gold - Gordon

Question 12

2 examples of displacement reactions?

Answer 12

• Reacting a metal with a metal oxide (by heating)
• Reacting a metal with an aqueous solution of a metal compound

Question 13

What is rusting?

Answer 13

• Rusting is a chemical reaction between iron, water and oxygen to form hydrated iron(III)oxide
• Rusting is a redox process and it occurs faster in salty water since the presence of sodium chloride speeds up the reaction

Question 14

Rusting of Iron word equation?

Answer 14

Iron + Water + Oxygen → Hydrated Iron(III) Oxide

Question 15

Rusting of iron chemical equation?

Answer 15

4Fe(s) + 3O₂(g) + xH₂O(l) → 2Fe₂O₃.xH₂O(s)

Question 16

Methods for preventing iron rusting?

Answer 16

• Barrier Methods
• Galvanising
• Sacrificial corrosion

Question 17

How is rusting prevented using barrier methods?

Answer 17

• Rust can be prevented by coating iron with barriers that prevent the iron from coming into contact with water and oxygen
• Examples of barriers are oil and plastic
• However, if the coatings are washed away or scratched, the iron is once again exposed to water and oxygen and will rust

Question 18

How is rusting prevented using galvanising?

Answer 18

• Iron can be prevented from rusting making use of metals higher in reactivity than iron
• Galvanising is a process where the iron to be protected is coated with a layer of zinc
• ZnCO₃ is formed when zinc reacts with oxygen and carbon dioxide in the air and protects the iron by the barrier method.
• If the coating is damaged or scratched, the iron is still protected from rusting because zinc preferentially corrodes as it is higher up the reactivity series than iron.

Question 19

How is rusting prevented using sacrificial corrosion?

Answer 19

• Sacrificial corrosion occurs when a more reactive metal is intentionally allowed to corrode.
• An example of this occurs with ships’ hulls which sometimes have large blocks of magnesium or magnesium alloys attached
• The blocks slowly corrode and provide protection to the hull in the same way the zinc does by pushing electrons onto the iron which prevents it from being oxidised to iron(III) ions

Question 20

What is oxidation?

Answer 20

Oxidation is any reaction in which a substance gains oxygen.

Question 21

What is reduction?

Answer 21

Reduction is a reaction in which a substance loses oxygen.

Question 22

What are redox reactions?

Answer 22

Where oxidation cannot occur without reduction happening simultaneously.

Question 23

What is the oxidising agent?

Answer 23

What supplies the oxygen. It accepts electrons.

Question 24

What is the reducing agent?

Answer 24

A reducing agent is a substance that donates electrons in a redox reaction.

Question 25

What is oxidation in terms of electrons?

Answer 25

Oxidation is the loss of electrons (OIL)

Question 26

What is reduction in terms of electrons?

Answer 26

Reduction is the gain of electrons (RIG)

Question 27

Observations from reactions between magnesium, iron, zinc with dilute sulfuric acid.

Answer 27

• Magnesium: Rapid bubbling, gas given off (hydrogen), metal dissolves.
• Zinc: Metal dissolves forming a colourless solution, gas given off slowly.
• Iron: Slow reaction, small bubbles seen.

Question 28

Define the term salt?

Answer 28

A salt is the ionic compound produced when a metal reacts with an acid.

Question 29

What is a spectator ion?

Answer 29

A spectator ion is an ion that does not participate in the chemical reaction and appears unchanged on both sides of the equation.

Question 30

Define the term corrosion?

Answer 30

The term corrosion means the degradation of a metal surface through a chemical reaction.

Question 31

Why is rusting bad?

Answer 31

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