galvanic cell anode cathode (1 Viewer)

[mr_vocab]

hi
i was wondering if anyone could help me
how do you know which one is the anode or the cathode in a galvanic cell. i know that oxidation occurs at the anode and reduction at the cathode but isnt there some rule about displacement and half potentials?
thanks in advance
nathan

 

[Farmerism]

say they give you two metals for the electrodes, to find out whether one is the anode or the cathode you can look at your data sheet for the standard potentials

if a metal is higher i.e. towards the potassium reaction, then that means that it is more ready to lose it's electron, so its more readily oxidised, hence the metal further up the series is the anode

hope that helps

 

[Farmerism]

also because the metal is further up = more reactive = more readily oxidised, then it is a strong reductant, and will displace a metal thats further down the series.

isnt there some rule about displacement and half potentials?

the rule for displacement thingy, if this is what youre asking about.. is that metals will react mre vigourously when they are further a part in the series
this also means that the voltage produced by them will also be greater than those metals whose positions are closer together react.

um also, with reference to half potentials, metals that oxidise tend to have the minus in front of their potential difference, so you coudl also look out for this to see whether its an anode or cathode

 

[mr_vocab]

thanks alot

just what i was after
cheers
nathan