11 mark
In a fuel cell ............1........... energy is converted to ..................2................ energy.
| 1 | 2 |
A | electrical | heat |
B | chemical | electrical |
C | potential | chemical |
D | chemical | heat |
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Hydrogen Fuel Cells (Cambridge (CIE) O Level Chemistry): Multiple Choice Questions
Exam code: 5070
2 hours31 questions
21 mark
Hydrogen-oxygen fuel cells can be used to power motor vehicles.
What is the correct balanced symbol equation for the reaction that occurs in a hydrogen-oxygen fuel cell?
H2O → H2 + O2
H2 + O2 → 2H2O
2H2 + O2 → 2H2O
H2 + O2 → H2O
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31 mark
A fuel cell produces electricity.
Which two substances are supplied to the fuel cell?
hydrogen and water
hydrogen and oxygen
water and oxygen
hydrogen and carbon dioxide
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41 mark
What does a hydrogen–oxygen fuel cell produce?
electricity and water
heat and carbon dioxide
hydrogen and oxygen
electricity and carbon dioxide
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51 mark
Which is a disadvantage of using a hydrogen–oxygen fuel cell instead of a petrol engine in a car?
Hydrogen is difficult to store in a vehicle.
The fuel cell produces carbon dioxide.
The fuel cell works only at high temperatures.
The fuel cell must be recharged from the mains.
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11 mark
Which of the following is an advantage of a hydrogen fuel cell to power a car?
Fewer moving parts than an internal combustion engine, so less energy is wasted.
The reaction is endothermic, so the engine does not overheat.
They produce carbon dioxide, which does not contribute to acid rain.
Hydrogen is easier and cheaper to store in a vehicle than gasoline.
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21 mark
What are the products made by a hydrogen-oxygen fuel cell?
1 Water
2 Oxygen
3 Hydrogen
1 only
1 and 2
2 and 3
1, 2 and 3
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31 mark
These statements refer to hydrogen and its use as a fuel.
Both water and hydrocarbons can be used as a source of hydrogen.
In a fuel cell hydrogen reacts with oxygen to generate electricity.
The reaction taking place in a fuel cell is a redox reaction.
1 and 2 only
1 and 3 only
2 and 3 only
1, 2 and 3
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41 mark
Three statements comparing gasoline (petrol) combustion engines with hydrogen-oxygen fuel cells are shown
The combustion of gasoline and the formation of water are both exothermic processes with a positive enthalpy change, ΔH.
Combustion engines are more polluting than fuel cells because incomplete combustion produces carbon monoxide and particulates.
Gasoline is more difficult and expensive to store in a vehicle than hydrogen.
Which statements are correct?
1 and 2
2 only
2 and 3
1, 2 and 3
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51 mark
Which substance is produced by a petrol engine but not by a hydrogen–oxygen fuel cell?
water
carbon dioxide
hydrogen
oxygen
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61 mark
What is the correct balanced symbol equation for the overall reaction in a hydrogen-oxygen fuel cell?
2H2 → 4H+ + 4e–
4H+ + O2 + 4e– → 2H2O
2H2 + O2 → 2H2O
2H2O → 2H2 + O2
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11 mark
Each row gives an advantage of using a hydrogen–oxygen fuel cell instead of a petrol engine in a car, together with a reason for that advantage.
In which row does the reason support the advantage?
Advantage | Reason | |
|---|---|---|
A | No carbon dioxide is produced | so the car does not add to climate change while it is being driven |
B | Hydrogen is a renewable fuel | because hydrogen can be obtained from the air |
C | The fuel cell is more efficient | because the fuel cell produces no heat at all |
D | Hydrogen is safer than petrol | because hydrogen is more flammable than petrol |
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21 mark
A petrol engine and a hydrogen–oxygen fuel cell are both used to power cars.
Both of them produce water.
Which statement explains why only the fuel cell is described as non-polluting?
The fuel cell produces water.
Water is the only chemical product of the fuel cell.
The fuel cell produces liquid water rather than water vapour.
Water is not a chemical product of the petrol engine.
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31 mark
The table compares a hydrogen–oxygen fuel cell with a petrol engine, both used to power a car.
Which row is correct?
Produces carbon dioxide | Produces water | Releases energy to the surroundings | |
|---|---|---|---|
A | fuel cell only | both | petrol engine only |
B | petrol engine only | both | both |
C | petrol engine only | petrol engine only | both |
D | both | fuel cell only | fuel cell only |
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41 mark
Which statement about using a hydrogen–oxygen fuel cell instead of a petrol engine in a car is correct?
Hydrogen is cheaper than petrol.
Hydrogen is less flammable than petrol.
More energy is released per gram of hydrogen than per gram of petrol.
Hydrogen can be obtained from the air.
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51 mark
A city replaces its diesel buses with buses powered by hydrogen–oxygen fuel cells.
Each row gives a disadvantage of using a fuel cell instead of a diesel or petrol engine, together with a reason for that disadvantage.
In which row does the reason support the disadvantage?
Disadvantage | Reason | |
|---|---|---|
A | Hydrogen is difficult to store on the bus | because hydrogen is a gas at room temperature |
B | The fuel cell pollutes the air | because water vapour leaves the exhaust |
C | Hydrogen is expensive to produce | because hydrogen has to be separated from the air |
D | The fuel cell must be recharged regularly | because the fuel cell stores a fixed amount of energy |
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