Q.

Consider the above electrochemical cell where a metal electrode (M) is undergoing redox reaction by forming M+ (MM++e-). The cation M+ is present in two different concentrations c1 and c2 as shown above. Which of the following statement is correct for generating a positive  cell potential  [2026]

1 If c1 is present at cathode, then c1<c2  
2 If c1 is present at anode, then c1>c2  
3 If c1 is present at anode, then c1=c2  
4 If c1 is present at cathode, then c1>c2.  

Ans.

(4)

(1) If C1 is at anode  cell reaction

      M+(C2)M+(C1)

      Ecell=-0.059logC1C2

       Ecell>0C1<C2

(2) If C1 is at cathode

       M+(C1)M+(C2)

       Ecell=-0.059logC2C1>0

      C2<C1