Answer to Question #154760 in Physical Chemistry for Rana

Question

A galvanic cell is constructed by coupling Ag and Cd electrodes dipped in 0.5 M Silver Nitrate and 0.25 M CdS04 respectively at 25°C. Write the cell scheme, cel! reaction, and calculate emf of the cell. Given that SRPs of Ag and Cd are +0.80 V and ▪ -0.40 V respectively.

Answer 1

Cell scheme: Cd²⁺ (0.25M)/Cd//Ag⁺ (0.5M)/Ag

Cell reaction: 2Ag⁺ + Cd----> Ag + Cd²⁺

E°= E°_Ag - E°_Cd

E°= 0.80 - (-0.40)

E°= 1.20V

Now let's find E using Nernst equation

E=E° - 0.059/n log[Cd²⁺]/[Ag⁺]²

E= 1.20 - 0.0591/2 log[0.25]/[0.50]²

E= 1.20- 0.02955log1

E= 1.20 - 0

E= 1.20V