In aqueous media, i convert nickel nitrate to nickel hydroxide for coating. I use porous nickel plate as cathode, under cathodic current nickel plate is coated with Ni(OH)2. I want to calculate amount of Ni(OH)2 but i am confused since both Ni ions in hydroxide and nitrate same state (+2).
I need to calculate theoretically then i measure the weight of coated Ni(OH)2 so that i can compare utilization of different process and experimental parameter.
Thanks in advance
If you weight it before and after, you can calculate the difference. The added weight should be Ni(OH)2. I didn't understand what is the problem.
As I understand Turan wants to calculate the theoretical meaning
Dear Ademario, as Svetlana state i want to calculate theoretically. To make it clear we can consider tüm example of electroplating of nickel. I can calculate amount of plated nickel by Faraday law [(current*time)/(Faraday Constant)]*((molar mass of nickel)/(number of exchanged Electron)]. Like in the case of nickel Electroplating, i want To calculate amount of plated nickel hydroxide theoretically. Faraday law does not work since state of nickel ion in nitrate and hydroxide is same, in other words number of exchanged elextron is zero
This question iş important for me because suppose i want to plate 2 grams of nickel hydroxide, how should i adjust current and time?
I am not an expert in coating.
Nevertheless, as far as I understood, Ni does deposit in your Ni plate as Ni(OH)2, without changing its oxidized state. In this case, you wouldn't have charge exchange. The cathodic state of the plate would be responsible for pulling the ions towards the plate, but the voltage that you apply is probably insufficient to donate electrons to your Ni ions.
So, what rules the ion transportation is the pull of the voltage and the mechanical resistance that the solvated Ni ions will face to cross from where they are in the midst of your solution to the surface of the plate.
Thus, you should look for electrophoresis models to calculate what amount of ions you can transport. The electrophoresis equations for these models normally take into account the voltage, the ion size (Ni ion + solvation layer), the ion charge, the temperature, the solvent - I am sure you will find equations for water - and the total ionic strength.
In your case, pH is not much of concern, since you are not dealing with proteins or amino acids that can change their charge state according to the pH of the solvent - the charge state of your ion is constant.
I hope these reasonings will help you. And please, keep me posted with your progress. I would be curious to know whether what I elaborated here really worked.
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