Electrochemical Thermodynamics

An iron sample (surface area of 3.3 cm^2) was protected by nickelization in a solution containing 0.1 M NiSO4 and 1 M H2SO4 at a current of 0.28 A for 30 min. Question: What will be the sample weight increase after the process of nickelization upon 62% current efficiency? Please show step by step solution.

Dissolution of alloy

A silver-20% gold alloy sample (1 cm diameter and 0.2 cm height) is subjected to a selective silver dissolution in 0.1 M HNO3 at current density of 1 mA/cm^2. Question: How long will it take until the total amount of silver is dissolved? Assume the average density of 8 g/ cm^3 for the alloy sample.

Final Overpotential

How long will it take to dissolve 2 mg of metal A (atomic weight 100) in a solution containing A^2+ from a metal electrode with area of 1.5 cm^2 at an overpotential of n = 0.2 V? The exchange current density (jo) for A is 3x10^-3 A/cm^2, the temperature T=298 K and the symmetry factor Beta=0.4. What will be the final overpotential (n) to satisfy the completetion of the deposition process?

Diffussion controlled electrolysis

Diffussion controlled electrolysis proceeds on (a) planar and (b) spherical electrode under the conditions: n = 1, C = 1 mM, A= 0.04 cm^2, D = 1.5x10^-5 cm^2/s. Calculate the current (i) in both cases at t = 0.5, 1, 3, 10 sec. How long can the electrolysis proceeed before the current at the spherical electrode exceeds that at the planar electrode by 10%?

Diffusion limiting

Calculate the diffusion limiting current for the oxidation of an organic compound at an electrode in stagnant solution. Assume 6 electrons are involved in the reaction (n=6). C(org) = 0.01 M, D(org) = 2x10^-5 cm^2/s. Calculate the transition time (tau) for the system at a current density of 0.3 A/cm^2.