Unit 4

Question 1

What does reactivity mean?

Answer 1

how vigorously a substance chemically reacts

Question 2

How can metals be ordered by their reactivity?

Answer 2

by comparing their reactions with water, acid,or oxygen

Question 3

What name is given to a list of metals ordered by their reactivity?

Answer 3

reactivity series

Question 4

In terms of electrons, what makes some metals more reactive than others?

Answer 4

they lose their outer shell electron(s) more easily

Question 5

Why are gold and silver found naturally as elements in the Earth’s crust?

Answer 5

they are very unreactive

Question 6

What is an ore?

Answer 6

rock containing enough of a metal compound to be economically worth extracting

Question 7

How are metals less reactive than carbon extracted from their ores?

Answer 7

reduction with carbon

Question 8

In terms of oxygen, what is oxidation?

Answer 8

addition of oxygen

Question 9

In terms of oxygen, what is reduction?

Answer 9

removal of oxygen

Question 10

Why can metals like potassium and aluminium not be extracted by reduction with carbon?

Answer 10

they are more reactive than carbon

Question 11

How are metals more reactive than carbon extracted from their ores?

Answer 11

electrolysis

Question 12

What is a displacement reaction?

Answer 12

a more reactive substance takes the place of a less reactive substance in a compound

Question 13

What is an ionic equation?

Answer 13

equation which gives some substances as ions and has spectator ions removed

Question 14

What type of substance is given as ions in an ionic equation?

Answer 14

ionic compounds in solution (or liquid)

Question 15

What is a spectator ion?

Answer 15

ion that is unchanged in a reaction

Question 16

What is a half equation?

Answer 16

equation that shows whether a substance is losing or gaining electrons

Question 17

In terms of electrons, what is oxidation?

Answer 17

loss of electrons

Question 18

In terms of electrons, what is reduction?

Answer 18

gain of electrons

Question 19

What is electrolysis?

Answer 19

the process of using electricity to extract elements from a compound

Question 20

What is the name of the positive electrode?

Answer 20

anode

Question 21

What is the name of the negative electrode?

Answer 21

cathode

Question 22

What is an electrolyte?

Answer 22

a liquid or solution that contains ions and so can conduct electricity

Question 23

Where are metals formed?

Answer 23

cathode

Question 24

Where are non-metals formed?

Answer 24

anode

Question 25

How can ionic substances be electrolysed?

Answer 25

by melting or dissolving them, and then passing a direct current through them

Question 26

Why can solid ionic substances not be electrolysed?

Answer 26

they do not conduct electricity, or the ions cannot move

Question 27

In the electrolysis of solutions, when is the metal not produced at the cathode?

Answer 27

when the metal is more reactive than hydrogen

Question 28

In the electrolysis of a metal halide solution, what is produced at the anode?

Answer 28

halogen gas

Question 29

In the electrolysis of a metal sulfate solution, what is produced at the anode?

Answer 29

oxygen

Question 30

What is the equation for the ionisation of water?

Answer 30

H2O(l) ➞ H+(aq) + OH−(aq)

Question 31

What metals are extracted from ionic compounds by using electrolysis?

Answer 31

metals that are more reactive than carbon

Question 32

In the electrolysis of aluminium oxide, why is the aluminium oxide mixed with cryolite?

Answer 32

to lower the melting point

Question 33

In the electrolysis of aluminium oxide, what are the anodes made of?

Answer 33

graphite

Question 34

In the electrolysis of aluminium oxide, why do the anodes need to be replaced?

Answer 34

they react with the oxygen being formed