MHT CET202519 Apr 2025Evening ShiftChemistryElectrochemistryActual
For the cell, ^ Zn _ (s) | Zn ⁺²(1 M ) | | Ag ⁺¹(1 M ) | Ag _ (s) ^ If concentration of Zn ⁺² decreases to 0.1 M at 298 K . then emf of cell
Options
- Aincreases by 0.0592 V
- Bdecreases by 0.0592 V
- Cincreases by 0.0296 V
- Ddecreases by 0.0296 V
Correct answer
C. increases by 0.0296 V
Step-by-step solution
The electrochemical cell is represented as Zn_ (s) | Zn²⁺ (1 M ) Ag^+ (1 M ) | Ag_ (s) . Cell Reactions and Electron Transfer At the anode: Zn_ (s) Zn²⁺_ (aq) + 2e⁻ At the cathode: 2 Ag^+_ (aq) + 2e⁻ 2 Ag_ (s) The overall cell reaction is Zn_ (s) + 2 Ag^+_ (aq) Zn²⁺_ (aq) + 2 Ag_ (s) , with n = 2 electrons transferred. Applying the Nernst Equation The Nernst equation at 298 K is E_ cell = E^0_ cell - 0.0592 n Q , where the reaction quotient Q = [ Zn²⁺ ] [ Ag^+ ]^2 . Initially, with [ Zn²⁺ ] = 1 M and [ Ag^+ ] = 1 M