C7.5 Batteries and Chemical cells- Chemistry Paper 1 Flashcards
What is a cell?
A system that contains chemicals which react and produce electricity
What does a cell contain?
2 different metal electrodes in contact with an electrolyte.
What affects a cells voltage?
The type of electrode used and the concentration of ions in the electrolyte
The bigger the difference in reactivity of the electrodes….
the bigger the voltage of the cell
What causes the voltage of a cell to become 0?
When there’s no difference in reactivity- either because the electrodes are made of the same metal or because the reactivity of the metals is the same
The higher the concentration of ions in the electrolyte…
the higher the voltage will be
What happens as the ions in the electrolyte react?
Their concentration will slowly decrease and so will the voltage of the cell. Eventually, the voltage will drop to 0 and the cell will stop working.
How is a battery formed?
By connecting 2 or more cells together in series
What happens in non-rechargeable batteries?
One of the reactants are used up (ions or electrodes) and so reaction can’t happen and electricity can’t be produced ever again.
What happens in a rechargeable battery?
Applying a current will reverse the reaction and recharge the battery
What is an example of a non-rechargeable battery?
An alkaline battery
What’s a fuel cell?
An electrical cell that’s supplied with a fuel and oxygen
What happens to the fuel in a fuel cell when it enters the cell through one side?
It becomes oxidised and sets up a potential difference within the cell which powers the device
What happens to the oxygen in a fuel cell when it enters through the opposite side?
It reacts to form water
What’s an example of a fuel cell?
A hydrogen-oxygen fuel cell
