A solution at 25 degrees C contains 1.0M Cd2+, 1.0M Ag+, 1.0M Au3+, and 1.0M Ni2+ in the cathode compartment of an electrolytic cell. Predict the order in which the metals will plate out as the voltage is gradually increased.
2007-04-11 17:31:42 · 3 answers · asked by ChEMIsTrY ChICkiE 1 in Science & Mathematics ➔ Chemistry
Eo(Au/Au3+)> Eo(Ag/Ag+)>Eo(Cd/Cd2+) >Eo(Ni/Ni2+)
so the order will be,
Au,Ag, Cd,Ni
that one which requires lower voltage is placed first & the one which requires highest voltage is placed last.
2007-04-11 17:54:08 · answer #1 · answered by s0u1 reaver 5 · 0⤊ 0⤋
Lancenigo di Villorba (TV), Italy
In the cathodic compartment you undergo an aqueous solution where are present several metals ions, e.g. CADMIUM(II), SILVER(I), GOLD(III) and NICKEL(II) ions.
This aqueous solutions contains anyone of chemical stuffs in 1.0 M or Unitary Molarity Solutions.
W. H. Nernst assigned yet the electrochemical Standard Potentials that are referred to 1.0 M's Concentrations in aqueous solutions at 25°C : these values are the following ones :
E°,Cd++/Cd° = -0.40 V
E°,Ag+/Ag° = +0.79 V
E°,Au+++/Au° = +1.50 V
E°,Ni++/Ni° = -0.25 V
As you know, when you refer to Ideal Cathodic Treatments avoiding Polarization or OverTension Phenomena you can follow the preceeding Potential as the Plating Trend.
The order in plating will be
First GOLD ; Second SILVER ; Third NICKEL ; Fourth CADMIUM.
I hope this helps you.
2007-04-12 02:32:41 · answer #2 · answered by Zor Prime 7 · 0⤊ 0⤋
Au , Ag, Cd, Ni
2007-04-11 17:43:50 · answer #3 · answered by ag_iitkgp 7 · 0⤊ 1⤋