[Borek]

I can see where the 0.0592 (nerst) and the 6 log (pH6) comes from.

Beware - there are two integer numbers you have to understand - 6 (number fo electrons) and 14 - [H⁺ ] power in the reaction quotient.

Where did the 1.33 come from?

From the table of standard potentials.

[Morphic flip]

I understand where the integers come from, just the 1.33 that threw me.
So if I worked out I^- to I₂ and H₂O₂, how would I tell if Cr₂O₇^2- oxidises them or not.
How would the figures from the working`s tell me? What am I comparing them to?
Thank`s.

[Borek]

You have to look for the table of standard potentials, they are present in most textbooks and handbooks, I am more then sure that you will be ablee to Google one in no time. Insert standard potentials into Nernst equation and calculate real potentials for all three solutions - then compare them.

[Morphic flip]

thank`s again.