Electrochemistry and Buffer

What is a galvanic cell? Draw a diagram of a Daniell cell. Calculate the emf of the following cell at 25°C. Fe/Fe²⁺(0.6 M)//Sn²⁺(0.2 M)/Sn. Given: E°_Fe²⁺/Fe = −0.44 V and E°_Sn²⁺/Sn = −0.14 V.

Define salt bridge. What is the role of salt bridge? From the given information, answer the following questions. Ni → Ni²⁺ + 2e⁻, E° = 0.24 V; Cd → Cd²⁺ + 2e⁻, E° = 0.40 V; [Ni²⁺] = 0.1 M and [Cd²⁺] = 0.01 M. i) Identify anode and cathode while constructing the galvanic cell with reasons. ii) Write the symbolic representation of the galvanic cell when the above given electrodes are coupled. iii) Calculate the EMF of the galvanic cell at 25°C.

The standard reduction potentials of Cd²⁺/Cd and Ni²⁺/Ni electrodes are −0.403 V and −0.25 V respectively. Construct a galvanic cell using these electrodes so the standard emf of the cell becomes positive. For what concentration of Cd does the emf of the cell at 25°C become zero, if the concentration of Ni is 0.01 M?