JEE Advanced2011ChemistryElectrochemistryActual
Consider the following cell reaction, array cc & 2 Fe ( s )+ O ₂(g)+4 H ⁺(a q) & 2 Fe ²⁺(a q)+2 H ₂ O (l), E^ =1.67 ~V At & [ Fe ²⁺ ]=10⁻³ M , P ( O ₂ )=0.1 ~atm array and pH =3 , the cell potential at 25^ C is
Options
- A1.47 ~V
- B1.77 ~V
- C1.87 ~V
- D1.57 ~V
Correct answer
D. 1.57 ~V
Step-by-step solution
The half reactions are Fe (s) Fe ²⁺( aq )+2 e⁻ 2 array r O ₂(g)+4 H ⁺+4 e⁻ 2 H ₂ O +2 Fe (s) + O ₂(g)+4 H ⁺ 2 Fe ²⁺(a q)+2 H ₂ O (l) E=E^ - 0.059 4 (10⁻³ )^2 (10⁻³ )^4(0.1) =1.57 ~V array