Electrochemistr...

Given below are the half- cell reactions
Mn²⁺ + 2e^‒ → Mn; E^o = ‒ 1.18e V
2(Mn³⁺ + e^‒ → Mn²⁺) E^o = + 1.51e V
The E^o for 3 Mn²⁺ → Mn + 2Mn³⁺ will be

What is the cell potential (standard emf, E°) for the reaction below ?
[E°_{(Fe²/(aq)Fe)} = 0.44 V and E°_{(O2(g)/H2O/OH ^‒ )} = + 0.4V]
2Fe (s) + O₂ (g) + 2H₂O (l) ⇌ 2Fe²⁺ (aq) + 4OH ^‒ (aq)

Zinc is used to reduce iron because

Aluminium displaces hydrogen from acids but copper does not. A galvanic cell prepared by combining Cu / Cu²⁺ and Al/ Al³⁺ has an emf of 2.0 V at 298 K. If the potential of copper electrode is +0.34 V, that of aluminimum electrode is

The standard emf. of a cell Zn/Zn²⁺|| Fe²⁺/Fe, if electrode potentials for (Zn/Zn²⁺) and (Fe²⁺/Fe) are 0.763 V and - 0.44 V respectively is

The electrochemical cell shown below is a concentration cell. M / M²⁺ (saturated solution of a sparingly soluble salt, MX₂) 11M²⁺ (0.00001 mol dm^-3/ M) . The emf of the cell depends on the difference in concentration of M²⁺ ions at the two electrodes. The emf of the cell at 298 is 0.059 V. The value of ∆G (kJ mol^-1 ) for the given cell is (take 1F = 96500C mol^-1 )