Electrolyse: optimal under high voltage or high ampFre 1

[Doryan]

Hi, this might seem a silly question to experts, but analytical chemistry is not my cup of tea.

When electrolysing a certain fluid, what is the best thing to do with your electrical power ? Transform it to be high voltage or high on ampéres ?

Or could it perhaps be an in between thing ? Is there a certain proportion between voltage and ampères to keep in mind ? Are there different characteristics for various types of fluids ?

I'm looking for every little bit of information regarding electrical power towards an electrolytical chemical process.

- Thanks, Doryan

 

[petroni]

My answer: depending on the conductivity on the fluid the voltage preferably should be as low as possible. You are setting the Amps and the voltage goes up to whatever it takes to reach the amps. There is (as far as I know) an exception. If you have two metals in the same solution you can plate them out separately by applying different voltages.

 

[Doryan]

Thanks petroni.

But does the kind of electrical power really manipulate (speed up) the chemical process, or does it just depend on how fast the electrolyte can perform ?

 

[petroni]

Hello again,

The higher the current the faster the plating.
Conductivity of the solution is one parameter that influence how high the voltage will be. But it will not effect plating speed.
The current during a given moment will "plate" a certain amount of ions. Therefore amount of Ah introduced is responding to amount of ions that is reduced.
I was not sure I understood your question, but get back again if there is something else you mean
rgds
Petroni

 

[Doryan]

Thanks again man.

This is all I needed to know. You really helped me.

- peace, Doryan

 

[Doryan]

Oh yeah, an additional question;

Does heating up the electrolyte makes the chemical process go faster ?

 

[Zoobie]

I can't speak to the details of the kinetics of the electrochemical reaction but increased temperature will increase the electrolyte conductivity. This will have the effect of reducing the amount of power required. Often electrochemical reactions are accompanied by thermochemical reactions or by diffusion near the electrodes. These will be affected by temperature.

As an example, the electrolysis of salt brines at relatively low temperatures in a properly designed cell without a 'salt bridge' will produce sodium hypochlorite. At higher temperatures (and different pH conditions) sodium chlorate will be formed. In both cases the same electrochemical reactions are occuring. The thermochemical reactions however are not the same.

I hope I haven't provided a confusing answer. As I do not know what process you are dealing with, I can only offer some generalizations.