Fuel Cells Flashcards
Name an example of a fuel cell
Hydrogen fuel cell
What are the reactants in a hydrogen fuel cell?
Hydrogen and Oxygen
Which electrode is the negative one in fuel cells?
Anode
as oxidation LOSS happens here
Which electrode is the positive one in fuel cells?
Cathode
as reduction GAIN happens here
At which electrode is hydrogen inputted?
The anode
At which electrode is oxygen inputted?
The cathode
Is hydrogen oxidised or reduced in a hydrogen fuel cell?
Oxidised
it loses electrons
Is oxygen oxidised or reduced in a hydrogen fuel cell?
Reduced
it gains electrons
What is the half-equation that occurs at the anode?
2H2 → 4H+ + 4e-
What is the half equation that occurs at the cathode?
O2 + 4H+ + 4e- → 2H2O
What is the waste product of hydrogen fuel cells?
Water
What are the advantages of hydrogen fuel cells compared to chemical cells
- Only requires Hydrogen and Oxygen which are renewable vs chemical cell reactants run out and need to be recharged
- Only produces water instead of CO2 and other pollutants
- They don’t have to be recharged vs in chemical cells when one of the reactants runs out then the reaction stops and the cell has to be reacharged
Name the disadvantages of hydrogen fuel cells compared to chemical cells
- Hydrogen is explosive when it reacts with air and so is difficult to store safely(it could leak) vs no dangerous fuel required in chemical cells
- Hydrogen is a gas which is more difficult to compress and then store and takes up more space than chemical cells
- To produce hydrogen for the fuel cell, energy is required for the electrolysis- this energy is usually from the burning of fossil fuels which emits CO2
What is the overall balanced equation of the reaction that takes place in the hydrogen fuel cell?
2H2+ O2 → 2H2O
Hydrogen supply to a fuel cell must be constant
True or False?
True
