Standard electrode potential of three metals X, Y and Z are $$-$$1.2 V, + 0.5 V and $$-$$ 3.0 V respectively. The reducing power of these metals will be

Standard electrode potential for Sn⁴⁺/Sn²⁺ couple is + 0.15 V and that for the Cr³⁺/Cr couple is $$-$$ 0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be

The electrode potentials for Cu²⁺_(aq) + e^$$-$$ $$ \to $$ Cu⁺_(aq)
and Cu⁺_(aq) + e^$$-$$ $$ \to $$ Cu_(s) are + 0.15 V and + 0.50 V respectively.

The value of E^o_cu²⁺/cu will be

Consider the following relations for emf of an electrochemical cell
(i)   EMF of cell = (Oxidation potential of anode) $$-$$ (Reduction potential of cathode)
(ii)  EMF of cell = (Oxidation potential of anode) + (Reduction potential of cathode)
(iii) EMF of cell = (Reductional potential of anode) + (Reduction potential of cathode)
(iv) EMF of cell = (Oxidation potential of anode) $$-$$ (Oxidation potential of cathode)

Which of the above relations are correct?