Chemical Cells And Fuel Cells

Question 1

cells and batteries

Answer 1

How do they work:
- place 2 metals in an electrolyte
- if you connect the 2 metals with a wire and voltmeter, you will see a potential difference and an electrical current will pass through the wire
- a chemical reaction is taking place one the surface of both metals, these reactions produce electricity
* a cell can only produce electricity for a certain amount of time before the reactants are used up
* cells only produce electricity if we use metals with different reactivities
(The greater the difference in the reactivity of the metals, the greater the potential difference)

Batteries are cells connected together in series to produce greater voltage

Question 2

Fuel cells

Answer 2

• in fuel cells we react a fuel with oxygen to produce electricity
• hydrogen oxygen fuel cells use hydrogen as their fuel and the only waste product is water
• useful in cars and spacecraft

Question 3

Pros and cons both

Answer 3

• hydrogen fuel cells will produce electricity as long as hydrogen is being provided
• chemical cells and batteries run out and need to be recharged
• hydrogen fuel cells don’t get less sufficient the longer they run
• chemical cells and batteries can store less electricity the more they are charged so they will have to be replaced eventually
• hydrogen fuel cells run on hydrogen which is an explosive gas and difficult to store safely
• chemical cells and batteries don’t require dangerous fuels
• hydrogen fuel cells produce a lower potential difference so several are needed together
• chemical cells and batteries can produce greater potential difference