[TheVanquished]

probably an acidic solution where u bubble oxygen into it?

[Borek]

probably an acidic solution where u bubble oxygen into it?

Very good answer Have a snack

Inserting platinum electrode into solution will help measure the potential, but it won't change redox reaction.

well probably i may be inaccurate at a higher level but this will do for my level. honestly, this is the only information i have for the question. So say if you only have these equations to compare with what do you think would be the appropriate answer?

IMHO it is impossible to answer this question correctly at this level. That's why different sources give conflicting answers.

[TheVanquished]

Firstly thanks for the snack 

Well is there an answer which is "more correct"?

[Borek]

Yes - but this the one that requires use of Nernst equation. You should write Nernst equation for the oxygen production, use known concentration of H⁺ of OH^- to calculate formal potential of the water/oxygen half reaction, and use this potential to predict what will be the product.

[TheVanquished]

oh my. i have no idea how to do that

[Borek]

Do you know what reaction quotient is?

[TheVanquished]

sorry but i have no idea

[Borek]

No need to be sorry if you have not learnt about it yet.

Take a look at these pages:

http://en.wikipedia.org/wiki/Reaction_quotient

http://www.ph-meter.info/pH-Nernst-equation

(you may finish reading after Nernst equation for permanganate reaction).

[cliverlong]

probably an acidic solution where u bubble oxygen into it?

Very good answer Have a snack

Inserting platinum electrode into solution will help measure the potential, but it won't change redox reaction.

OK, I get it !

Thanks to both of you.

Just to finish that off, what happens at the platinum surface that enables the voltage to be measured?

Clive

[Borek]

Just to finish that off, what happens at the platinum surface that enables the voltage to be measured?

Last time I asked answer was "we are not sure". But it was about 20 years ago.

[cliverlong]

Just to finish that off, what happens at the platinum surface that enables the voltage to be measured?

Last time I asked answer was "we are not sure". But it was about 20 years ago.

For some reason what you wrote brought a smile to my face (strange person that I am)

Evidence >> 

[renge ishyo]

Last time I asked answer was "we are not sure". But it was about 20 years ago.

I always thought the platinum was acting as a catalytic surface to facilitate the conversion of H₂ to 2H⁺ back and forth

[Borek]

I always thought the platinum was acting as a catalytic surface to facilitate the conversion of H₂ to 2H⁺ back and forth

Yes, especially if covered with platinum blak it lover overpotantial of such reaction. But as I understand the question ikt asks about why pltinum electrode has the same potential as the redox couple present in the solution - in the other words, why it can work as ORP electrode - and here answer is not that obvious.