1)

Consider the following cell reaction.

  2Fe(s)+O2(g)+4H+(aq)

                   2Fe2+(aq)+2H2O(l),  E°=1.67 V

At       [FE2+]=103M, P(O2)=0.1atm

and  pH=3 , the cell potential at 25° C is 


A) 1.47 V

B) 1.77 V

C) 1.87 V

D) 1.57 V

Answer:

Option D

Explanation:

The half reactions are

 Fe(s)Fe2+(aq)+2e×2

 O2(g)+4H++4e2H2O+2Fe(s)

  +O2(g)+4H+2Fe2+(aq)+2H2O(l)

  E=E00.0594log(103)2(103)4)(0.1)=1.57V