What type of reaction takes place in a chemical cell?
Exothermic
Endothermic
No reaction occurs
Why does the voltage from a chemical cell that is connected in a circuit with a lamp eventually reach zero?
The lamp breaks
One of the reactants is used up
The circuit becomes broken
What is produced by a hydrogen-oxygen fuel cell?
Water and carbon dioxide
Carbon dioxide
Water
What happens to hydrogen molecules in a hydrogen-oxygen fuel cell?
They form hydrogen ions, H+, and electrons, e-
They form hydrogen ions, H-, and electrons, e+
They form hydrogen atoms, H
What happens to oxygen molecules in a hydrogen-oxygen fuel cell?
They react with electrons to form oxide ions
They react with hydrogen ions to form hydroxide ions
They react with hydrogen ions and electrons to form water
Which of these is a disadvantage of cars driven by hydrogen-oxygen fuel cells rather than by petrol engines?
They have fewer moving parts
There are fewer suitable filling stations
Hydrogen is flammable
What is the main reason why hydrogen is more difficult to store than diesel?
Hydrogen is a gas at room temperature but diesel is a liquid
Hydrogen can be liquefied by cooling it
Hydrogen can be stored under pressure
What is a strength of using hydrogen-oxygen fuel cells in manned spacecraft, compared to using chemical cells?
They produce electricity
They produce water that the astronauts can drink
They produce a voltage
What is a disadvantage of using solar photovoltaic cells to provide electricity in a spacecraft?
Photovoltaic cells have lots of moving parts
Photovoltaic cells release toxic byproducts
Photovoltaic cells only work when the spacecraft is in direct sunlight
In a hydrogen fuel cell used to power a car, where does the oxygen come from?
The air
A catalyst
The fuel