galvanic help (1 Viewer)

[sssona09]

hey, confused about how we look at the half equations when there are two DIFFERENT solutions in the whole cell setup
anyways this q
draw a diagram of a electrochemical cell represented by mg|mg2+||hg2+|hg, pt
what does this mean?
also how do we know what the half reactions are?

thank you

 

[Sp3ctre]

I find that sort of notation confusing myself, but basically you should recognise platinum as an inert electrode that doesn't actually take part in the reaction, so the reactions that are taking place is the oxidation of magnesium and reduction of mercury. You are given the reduction half-equations in the data sheet under the standard reduction potentials. You just need to know whether oxidation or reduction is taking place, if it's oxidation then you need to flip the half-equation.

 

[same1111]

We know that magnesium is oxidised because it is losing electrons( changes to +2 charge) and mercury is reduced because it gains electrons.

 

[sssona09]

I find that sort of notation confusing myself, but basically you should recognise platinum as an inert electrode that doesn't actually take part in the reaction, so the reactions that are taking place is the oxidation of magnesium and reduction of mercury. You are given the reduction half-equations in the data sheet under the standard reduction potentials. You just need to know whether oxidation or reduction is taking place, if it's oxidation then you need to flip the half-equation.

thank you man!