Please help. All solutions are the same when looking at similar questions on answers but it is not understandable. Please

[answerhappygod]

Please help. All solutions are the same when looking at similar
questions on answers but it is not understandable. Please help me
understand how to get to the answer!
1 consider the following electrode-solution interfaces, and
write the equation for the electrode
reaction that occurs when the potential moved in a negative
direction from a potential where
there is no electrode reaction (such a potential is also called
open-circuit potential)
Pt/Cu2+, Cd2+
Hg/Cd2+, Zn2+
2. Consider the following electrode-solution interfaces, and
write the equation for the electrode
reaction that occurs when the potential moved in a positive
direction from the open-circuit
potential, what is the open-circuit potential range?
Au/Sn2+, I-, Fe2+,