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Essential Chemistry for IGCSE - Chemical Changes (Section 5)

1
What is the major disadvantage of hydrogen fuel cells?
Answer
(B)
High cost of hydrogen production
2
What is a major benefit of using hydrogen fuel cells in automobiles?
Answer
(A)
Zero tailpipe emissions (only water)
3
Which half-reaction occurs at the cathode of a fuel cell?
Answer
(B)
Oxygen reduction
4
What does nuclear fission involve?
Answer
(A)
The splitting of atoms' nuclei.
5
Which gas is used as a fuel in a typical hydrogen fuel cell?
Answer
(C)
Hydrogen
6
Which fuel is often used as a fuel in nuclear reactors?
Answer
(B)
Uranium
7
Which of the following statements is true about nuclear fission?
Answer
(B)
It involves splitting of an atom's nucleus.
8
In a fuel cell, how does the hydrogen fuel participate in the reaction?
Answer
(A)
It releases electrons.
9
Which gas is required for a hydrogen fuel cell to function?
Answer
(C)
Oxygen
10
What type of reaction occurs at the cathode in an electrochemical cell?
Answer
(B)
Reduction
11
What is the source of hydrogen used in a fuel cell?
Answer
(A)
Hydrogen storage tank
12
Which of the following are considered forms of energy?
Answer
A
B
C
D
13
Which of the following is NOT a fossil fuel?
Answer
(D)
Wood
14
Which of the following is NOT a sign of a chemical change?
Answer
(C)
Change in state
15
What term describes a change in the state of a substance, such as from solid to liquid?
Answer
(B)
Physical change
16
Where does oxidation occur in an electrochemical cell?
Answer
(A)
The anode
17
What is the role of water in the reactor core?
Answer
A
D
18
What is used as the primary fuel source in nuclear reactors?
Answer
(C)
Uranium
19
Which type of energy production has the greatest negative impact on the environment?
Answer
(C)
Fossil fuels
20
How does the heat generated by nuclear fission create electricity?
Answer
(B)
It boils water to produce steam that drives a turbine.
21
Which of the following is a chemical change?
Answer
(C)
Burning paper
22
Which of these is NOT a byproduct of a hydrogen fuel cell?
Answer
(D)
Carbon Dioxide
23
What will happen to the temperature of the surroundings during a chemical reaction that releases energy?
Answer
(B)
It will increase
24
Which term represents the heat energy change in a chemical reaction?
Answer
(B)
Enthalpy
25
What is the role of uranium in a nuclear power plant?
Answer
(A)
To generate the heat.
26
What is an advantage of using natural gas as a fuel?
Answer
(C)
It is less polluting than coal.
27
What are the primary products of a hydrogen fuel cell's reaction?
Answer
(A)
Water and electricity
28
Which gas is consumed at the cathode in a hydrogen fuel cell?
Answer
(B)
Oxygen
29
What kind of molecules diffuse through a porous electrode?
Answer
(A)
Hydrogen and oxygen
30
What is meant by 'energy from radioactivity'?
Answer
(A)
Energy released during nuclear reactions.
31
What are the main emissions from the tailpipe of a hydrogen fuel cell vehicle?
Answer
(B)
Water vapor
32
What happens to the temperature of the surroundings during an endothermic reaction?
Answer
(B)
It decreases
33
What is the function of the electrolyte in an electrochemical cell?
Answer
(B)
To allow the movement of ions.
34
What is the primary source of energy for the combustion of fuels?
Answer
(B)
The bond making
35
What are the main reactants in a hydrogen fuel cell?
Answer
(A)
Hydrogen and oxygen
36
What happens in an endothermic reaction?
Answer
(B)
Heat is absorbed.
37
In a simple electrochemical cell, the voltmeter measures:
Answer
(B)
The voltage
38
Which component of a nuclear reactor slows down neutrons?
Answer
(D)
Moderator
39
Which part of a fuel cell is the side where hydrogen undergoes oxidation?
Answer
(C)
Anode
40
During an exothermic reaction, the energy of the system's products compared to the reactants is:
Answer
(B)
Lower
41
Which type of reaction requires energy to occur?
Answer
(A)
Bond breaking
42
Which of the following is a disadvantage of using fuel cells?
Answer
(B)
They require hydrogen
43
During which type of reaction are chemical bonds broken?
Answer
(A)
Bond breaking
44
What is the sign of ΔH for an endothermic reaction?
Answer
(A)
Positive
45
Which type of energy does a nuclear power plant primarily convert into electrical energy?
Answer
(C)
Nuclear
46
What type of charge does the anode have in a simple electrochemical cell?
Answer
(B)
Negative
47
Why are fuel cells attractive as an alternative to combustion engines?
Answer
(C)
Only water is emitted.
48
Which of the following is a primary advantage of fuel cells?
Answer
(A)
High efficiency
49
In a nuclear reactor, what is the purpose of control rods?
Answer
(B)
To control the rate of the chain reaction
50
What is the process happening at the anode in an electrochemical cell?
Answer
(B)
Oxidation