Topic 5 Cells and batteries Flashcards
What is an electrochemical cell
A basic system made up of 2 different electrodes in contact with an electrolyte
What is an electrolyte
A liquid that contains ions which react with electrodes
(Liquid that can conduct electricity)
What sets up a charge difference
Chemical reactions between the electrodes
How can the voltage of a cell be measured
A voltmeter can be added to the wires connecting the electrodes
What effects the voltage of a cell
The type of electrodes -(different ions or electrodes react differently with different electrolytes)
The bigger the difference in reactivity the bigger the voltage
How is a battery formed
By joining 2 or more cells together in series
(The voltages of the cells are combined)
What happens when one of the reactants are used up in a battery
The reaction can’t happen and no electricity is produced
Why are some batteries non rechargeable
Because the products can’t be turned back into the reactants
(Irreversible reaction)
Once the reactant is used up no more electricity can be made
Why are some batteries rechargeable
The reaction can be reversed by connecting it to an external electric current
