0 votes
38 views
in ElectroChemistry by (460 points)
Calculate the exchange current density for a Zinc electrode immersed in a solution containing 0.1 M Zinc ions at 25 degrees Celsius, given that the standard potential of the Zinc half-reaction is -0.76 V and the transfer coefficient is 0.5. (Assume concentration polarization effects to be negligible.)

1 Answer

0 votes
by (370 points)
To calculate the exchange current density  i0  for the Zinc electrode, we can use the Butler-Volmer equation:i0 = n * F * A * k0 *  C_red ^*  C_ox ^1- where:n = number of electrons transferred in the half-reaction  for Zn, n = 2 F = Faraday's constant  96485 C/mol A = electrode surface area  we will assume it to be 1 cm for simplicity k0 = standard rate constant  we will assume it to be 10^-7 cm/s for simplicity C_red = concentration of reduced species  0.1 M for Zn ions C_ox = concentration of oxidized species  1 M for Zn metal, as it is in its pure form  = transfer coefficient  0.5 Now, we can plug in the values and calculate i0:i0 = 2 * 96485 * 1 * 10^-7 *  0.1 ^0.5 *  1 ^1-0.5 i0 = 192970 * 10^-7 * 0.3162i0 = 6.097 * 10^-5 A/cmSo, the exchange current density for the Zinc electrode immersed in a solution containing 0.1 M Zinc ions at 25 degrees Celsius is approximately 6.097 * 10^-5 A/cm.

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...