Essential Chemistry for IGCSE - Electricity And Chemistry (Section 3)
1
In which part of the electrolysis of copper (II) sulfate is there a transfer of copper ions?
Answer
(A)
From anode to cathode
2
What is the purpose of adding calcium fluoride (CaF₂) to the electrolyte used in aluminium extraction?
Answer
(B)
To lower the melting point.
3
What process is used to make chlorine from brine (concentrated sodium chloride solution)?
Answer
(C)
Electrolysis
4
In the electrolysis of aqueous copper(II) sulfate using inert electrodes, which of the following is true regarding the concentration of copper(II) ions?
Answer
(B)
It decreases
5
What is the role of the steel core in the high-voltage power cables?
Answer
(C)
To provide additional strength to the cable.
6
Which of the following is a benefit of electroplating?
Answer
(B)
To improve the appearance of metals
7
What is the main metal present in steel-cored aluminium cables?
Answer
(B)
Aluminum
8
Which of the following is produced during the electrolysis of sodium chloride solution?
Answer
A
B
D
9
What are the products formed when electrolyzing a dilute solution of sulfuric acid, H2SO4 (aq)?
Answer
A
B
10
In the electrolysis of alumina, what happens at the anode?
Answer
(B)
Oxide ions are oxidized to oxygen gas.
11
What does electrolysis do to a compound?
Answer
(B)
Decomposes the compound
12
What gas is produced at the anode during the electrolysis of molten aluminium oxide?
Answer
(B)
Oxygen
13
What is the process of breaking down an ionic compound using electricity called?
Answer
(A)
Electrolysis
14
Which of the following is a key step to protect metals from corrosion?
Answer
(A)
Electroplating
15
If you were to electroplate an iron key with copper, what is the role of the iron key?
Answer
(B)
Cathode
16
What is the source of aluminium oxide used in the electrolysis process?
Answer
(B)
Bauxite ore
17
In the electrolysis of molten lead(II) bromide, what is the oxidation state of lead in the electrolyte?
Answer
(B)
+2
18
What is the function of a diaphragm in the electrolysis of brine in the chlor-alkali process?
Answer
(D)
All of the above
19
During the electrolysis of concentrated hydrochloric acid, which product(s) will be formed?
Answer
A
B
20
What is the name of the process used to remove impurities from the aluminium ore?
Answer
(C)
Purification
21
During electrolysis of a copper(II) sulfate solution using inert electrodes, what happens at the cathode?
Answer
(B)
Copper metal is deposited
22
When electroplating an object with silver, why must the object be clean?
Answer
(B)
To ensure the silver coating sticks properly.
23
What is the name of the process used to produce chlorine gas from a concentrated solution of sodium chloride?
Answer
(C)
Electrolysis
24
What is the main product formed at the cathode during electrolysis?
Answer
(A)
Aluminium Metal
25
In the electrolysis of molten sodium chloride, what is the product formed at the cathode?
Answer
(B)
Sodium metal
26
What is the process of coating a metal with a thin layer of another metal called?
Answer
(B)
Electroplating
27
Which of the following statements explains why insulators do not conduct electricity?
Answer
(A)
Insulators have tightly bound electrons.
28
What type of materials would be best used for the insulation on the wires used in electrical circuits?
Answer
(C)
Plastics
29
Why are high-voltage power lines generally made of steel-cored aluminum cables?
Answer
(A)
Aluminum conducts electricity well, and steel adds strength.
30
In the electrolysis of copper(II) sulfate with copper electrodes, what happens to the mass of the anode and the cathode?
Answer
A
D
31
Which of the following is NOT a factor that determines the products of electrolysis?
Answer
(D)
The volume of the electrolyte
32
What is the primary function of cryolite in the electrolytic extraction of aluminum?
Answer
(B)
To lower the melting point of the electrolyte.
33
What is the purpose of electrolysis?
Answer
(A)
To separate compounds into their elements
34
When electroplating, the object to be plated functions as the:
Answer
(B)
Cathode
35
The process of separating a compound into its elements using electricity is called:
Answer
(C)
Electrolysis
36
Which substance is the electrolyte made of in the electrolysis of aluminium oxide?
Answer
(C)
A mixture of aluminium oxide and cryolite.
37
Which substance is the aluminum metal produced from during electrolysis?
Answer
(A)
Aluminum ions
38
Which electrode is the site of reduction?
Answer
B
C
39
What happens to copper atoms at the anode during the electrolysis of copper sulfate solution using copper electrodes?
Answer
(B)
They are oxidized
40
Which of the following materials is primarily used in making the electrodes in the electrolytic cell to extract aluminum?
Answer
(C)
Graphite
41
The cathode in electrolysis is defined as the electrode where:
Answer
(D)
Both reduction and electrons enter
42
In the electrolysis of dilute sulfuric acid, which gas is evolved at the anode?
Answer
(B)
Oxygen
43
Which of the following is an advantage of using copper electrodes in the electrolysis of copper sulfate solution?
Answer
(C)
The concentration of the copper sulfate solution remains constant.
44
What type of material is used as electrodes in the electrolytic cell for the extraction of aluminium?
Answer
(C)
Graphite
45
During electroplating, where does the metal coating come from?
Answer
(C)
The anode
46
Which of the following components are essential for the electrolytic extraction of aluminium?
Answer
A
C
D
47
Which of the following are essential for the electroplating of an object?
Answer
A
B
C
48
Which of the following are advantages of using steel-cored aluminum cables in high-voltage power lines?
Answer
B
D
49
What are the conditions necessary to perform electrolysis?
Answer
A
B
C
50
In the extraction of aluminium from bauxite ore, what is the role of the sodium hydroxide?
