Chemistry unit 5 Flashcards
What is a cell and what is a battery
A Cell contains chemicals that react to produce to make electricity.
What we know are batteries are just multiple cells put together
In a simple cell, how are the metals set up
The more reactive metal loses electrons more easily so the electrons pass from the more reactive metal to the less reactive metal ( Oxdiation reaction )
In a battery, which way is the more reactive metal
At the minus side so the less reactive metal is at the plus
What are the 2 factors that effect the voltage produced from the battery
-The Types of Electrodes: The greater the difference in reactivity between the two metals, the greater voltage that is produced.
-The types of Electrolytes: The type and concentration of the electrolyte solution matters as it reacts with the metal
How is a fuel cell different to electrolysis
the anode and cathodes are the other way around and in electrolysis, there is an external power supply whilst in a cell, it produces its own electricity
How do we get rechargeable batteries
unlike normal batteries where the metal is used up, the rechargeable batteries have a reverse reaction going on inside them so they can reverse the process.
Why do we use hydrogen fuel cells
-It renewable so it doesn’t harm the environment.
-As long as you keep putting fuel into it, it wont stop working
-The only waste product is water which is useful to us
What is a disadvantage of a hydrogen fuel cell
It can be tricky to store hydrogen as it is gas a room temperature so it is difficult to transport
How is electricity made from the fuel cell ?
The Oxidation reaction inside the fuel; cell is electrochemically started
What is the half equation at the anode in a hydrogen fuel cell
H2(g) -> 2e- + 2H+(aq)
What is the half equation at the cathode in a hydrogen fuel cell
4H+(aq) + O2(g) + 4e- -> 2H2O(g)
