The question says:

Calculate the standard e.m.f. of the cell at 298 K?

1) Ni (s) | Ni 2+^ (aq)|| Sn 2+^ (aq), Sn 4+^ (aq) |pt

.....

Will I have to use the Nernst equation? The questi does not even state if its standard or non standard? do i ignore the 298 K??

:confused::confused::confused:

The question says:

Calculate the standard e.m.f. of the cell at 298 K?

1) Ni (s) | Ni 2+^ (aq)|| Sn 2+^ (aq), Sn 4+^ (aq) |pt

.....

Will I have to use the Nernst equation? The questi does not even state if its standard or non standard? do i ignore the 298 K??

:confused::confused::confused:
Are you aware you have to calculate the reduction and oxidation? For instance, you would have E_0=E_{red}+E_{oxi} and will measure the voltage of the cell.

yes I know I need to calculate E cell which is E cathode - E anode

I'm not entirely sure of the next steps I must take alltogether and how? Please could you guide me on this? thanks

yes I know I need to calculate E cell which is E cathode - E anode

I'm not entirely sure of the next steps I must take alltogether and how? Please could you guide me on this? thanks

Well, this is never easy stuff - atleast I never found it very easy. I even had to look it up again: here is an example:

Zn(s) + Fe^2+ -----> Zn^2+ + Fe(s)

To calculate the cell voltage, you need to split the equation (hopefully your are aware of how to do this, which gives us:

Zn(s) -----> Zn2+ + 2e
Fe^2+ +2e -----> Fe(s)

Which are the two half-reactions as we have gathered you know about. You need to know the potentials required, so

Zn^2+ + 2e -----> Z^n where
E_0 = -0.76V

This equation needs to be reversed, so E_0 will be reversed also.

Zn(s) -----> Zn^2+ + 2e
E_0 = +0.76V
Fe^2+ +2e -----> Fe(s)
E_0 = -0.41V

You then add the two equations together.

ps. this is just an example. You will need to work this out yourself.

298K is a standard temperature so the question is about standard potentials. Pt is a standard "inert" electrode too--it doesn't get reduced or oxidized, but acts as a source or sink of electrons.

Your answer might be found here (http://en.wikipedia.org/wiki/Standard_reduction_potential)

298K is a standard temperature so the question is about standard potentials. Pt is a standard "inert" electrode too--it doesn't get reduced or oxidized, but acts as a source or sink of electrons.

Your answer might be found here (http://en.wikipedia.org/wiki/Standard_reduction_potential)

Yes, that's right. I've just explained that.

The Wiki page I referenced has a link to a list of standard electrode potentials, which will probably also be useful. These are often located in Chemistry textbooks, in the chapters that cover electrochemistry.

The Wiki page I referenced has a link to a list of standard electrode potentials, which will probably also be useful. These are often located in Chemistry textbooks, in the chapters that cover electrochemistry.

Ah yes, that is helpful.