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Essential Chemistry for IGCSE - Electricity And Chemistry (Section 6)

1
What type of materials are used as the electrodes in the electrolytic cell for the extraction of aluminum?
Answer
(B)
Graphite.
2
How does increasing the thickness of a wire affect its resistance?
Answer
(B)
Decreases the resistance.
3
Which statements correctly describe what happens during electroplating with copper? (Select all that apply)
Answer
A
B
4
Which of the following is the main metal used in high voltage electricity powerlines?
Answer
(C)
Aluminum
5
In electrolysis, what happens to the ions present in the electrolyte? (Select all that apply)
Answer
A
B
C
6
In the context of electrochemistry, what does the term 'oxidation' refer to?
Answer
(B)
Loss of electrons
7
In the electrolysis of water, what are the two gases produced?
Answer
(B)
Hydrogen and oxygen
8
During electroplating, what happens to the silver ions?
Answer
(B)
They are reduced at the cathode.
9
In the electrolysis of brine (concentrated NaCl solution), what substance is produced at the cathode?
Answer
(C)
Hydrogen gas
10
What is the name of the electrode where oxidation occurs in an electrolytic cell?
Answer
(B)
Anode
11
Which of the following are examples of redox reactions? (Select all that apply)
Answer
A
B
D
12
In the electroplating of an object with zinc, which statements are true? (Select all that apply)
Answer
A
B
D
13
Which of the following is the main source of aluminum ore?
Answer
(A)
Bauxite.
14
During electrolysis, what is the role of the external circuit?
Answer
(B)
To complete the circuit and allow the flow of electrons.
15
What is the name given to the process by which the products of electrolysis are formed?
Answer
(D)
Discharge
16
During the refining of copper, what happens to the impurities?
Answer
(C)
They form a sludge at the bottom.
17
Why is it important to keep very thick wires in the high-voltage power lines?
Answer
(B)
To decrease the resistance.
18
Which of the following is/are a correct description of the electrolysis process for extracting aluminum?
Answer
B
D
19
In an electrolytic cell, the cathode is the electrode where ______ occurs.
Answer
(B)
Reduction
20
What are the products of electrolysis of dilute sulfuric acid using inert electrodes?
Answer
(B)
Hydrogen and oxygen
21
Which material, if any, could be used in place of aluminum for high-voltage power lines without any change of function?
Answer
(C)
Copper
22
What happens at the cathode during the electrolysis of molten aluminum oxide?
Answer
(B)
Aluminum is produced.
23
What happens to the carbon anodes during electrolysis?
Answer
(B)
They react with oxygen to form carbon dioxide.
24
What is the definition of 'reduction' in terms of electron transfer?
Answer
(B)
Gain of electrons
25
In the electrolysis of molten sodium chloride (NaCl), what is formed at the cathode?
Answer
(A)
Sodium
26
What is the function of the inert electrodes in electrolysis, such as in the electrolysis of copper sulfate solution?
Answer
(D)
To provide a surface for the redox reactions to occur.
27
During the electroplating of iron with zinc, which of the following is correct regarding the iron object?
Answer
(B)
It acts as the cathode, and zinc ions are reduced on its surface.
28
In the electrolysis of a copper(II) sulfate solution using copper electrodes, what happens at the cathode?
Answer
(B)
Copper is deposited.
29
In high-voltage cables, how does the steel core contribute to the cable's functionality?
Answer
(C)
By increasing mechanical strength.
30
What is the name of the process that involves the transfer of electrons?
Answer
(D)
Redox
31
If inert electrodes are used, what is the result of the electrolysis of a copper (II) sulfate solution?
Answer
(B)
Copper is deposited and hydrogen is released.
32
What is the purpose of the inert electrodes in the electrolysis of copper sulfate solution?
Answer
(C)
To allow the reaction to happen at the electrodes without themselves reacting.
33
During the purification of bauxite ore, the ore is initially reacted with which substance?
Answer
(B)
Sodium hydroxide
34
What is the electrolyte in the electrolysis of water?
Answer
(B)
Acidified water
35
What happens at the anode during the electrolysis of aluminum oxide?
Answer
(D)
Oxide ions lose electrons.
36
Which of the following statements is correct regarding electroplating?
Answer
(B)
The electrolyte solution contains the ions of the metal to be plated.
37
What is the role of calcium fluoride (CaF₂) in the aluminum extraction process?
Answer
(B)
To decrease the melting point of the electrolyte.
38
What is the function of a siphon tube in the electrolytic cell used for aluminum extraction?
Answer
(B)
To remove the liquid aluminum metal from the cell.
39
During the electroplating of an object with silver, which of the following is true?
Answer
A
C
D
40
Which of the following statements is true about the electrolysis of molten sodium chloride? (Select all that apply)
Answer
A
B
41
Which of the following are true about the use of plastics and ceramics?
Answer
(A)
They are insulators.
42
What type of cell is an electrolytic cell?
Answer
(B)
Electrolytic
43
Which is a key step in the purification of copper by electrolysis? (Select all that apply)
Answer
A
B
C
D
44
In the refining of copper, the anode is made of:
Answer
(B)
Impure Copper
45
What is the overall reaction that occurs during the electrolysis of water?
Answer
(A)
2H₂O(l) → 2H₂(g) + O₂(g)
46
If a steel spoon is electroplated with silver, what would be the correct order of the setup?
Answer
(A)
Steel spoon as cathode, silver anode, silver nitrate electrolyte
47
What is the function of the inert electrodes in the electrolysis of copper sulfate solution?
Answer
(C)
To conduct electricity without undergoing a chemical change.
48
What is the purpose of using a silver anode in the electroplating of an object with silver?
Answer
(A)
To provide the silver ions.
49
Which of the following are used to cover electrical equipment to prevent shocks?
Answer
B
D
50
Which statement(s) is/are correct about the extraction of aluminum?
Answer
A
C
D