What would be the cell potential for the Galvanic cell which is represented by the electrochemical reaction: aligned & 2 Cr _ ( S ) +3 Fe ²⁺(0.02 M ) 2 Cr ³⁺(0.2 M )+3 Fe & E ^0 Fe ²⁺ / Fe =-0.42 ~V E ^0 Cr ³⁺ / Cr =-0.72 ~V aligned

Step-by-step solution

The cell reaction is 2 Cr + 3 Fe ²⁺ 2 Cr ³⁺ + 3 Fe . The standard cell potential E⁰_ cell is calculated as E⁰_ cathode - E⁰_ anode . E⁰_ cell = E⁰_ Fe ²⁺/ Fe - E⁰_ Cr ³⁺/ Cr = -0.42 - (-0.72) = 0.30 V . The number of electrons transferred in the balanced reaction is n = 6 . Using the Nernst equation at 298 K : E_ cell = E⁰_ cell - 0.0591 n [ Cr ³⁺]^2 [ Fe ²⁺]^3 E_ cell = 0.30 - 0.0591 6 (0.2)^2 (0.02)^3 E_ cell = 0.30 - 0.00985 0.04 0.000008 E_ cell = 0.30 - 0.00985 (5000) Since (5000) = (5 10^3) = (5) + 3 0.699 +