Fuel Cells

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, O^2-

• They react with hydrogen ions to form hydroxide ions, OH^-

• 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

• They emit little pollution

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