Topic 5- Chemical cells Flashcards
What do chemical cells produce?
A voltage/ potential difference
How do chemical cells produce a voltage?
-Atoms are oxidised/ loose electrons at the anode (it is negative)
-Free electrons move to positive cathode
When does the chemical cell stop working?
When one reactant is used up
What happens in a hydrogen-oxygen cell?
-Hydrogen looses electron and moves through anode to cathode
-React with oxygen at cathode to make water
What are the posistives for chemical fuel cells?
-Only produce water
-Keep producing fuel as long as reactants
What are the negatives for chemical fuel cells?
-Hydrogen has to be made (expensive + uses fossil fuels)
-Hydrogen is hard to store (takes up space + flammable)
How to make a stronger cell?
-Larger potential difference
-Use metals with greater difference in reactivity
Why do cells stop working?
-reactants run out and reaction stops
What is a battery?
-More than one cell connected in series
-Creates larger potential difference
How can we recharge batteries?
-Some batteries have the ability to reverse the reaction
