Chemistry Help Please.?

Question

I'm designing an electroplating experiment for chemistry and I want to investigate the effect voltage has on the speed/quality for electroplating.

I've found that if voltage is increased, then the electroplating will take place more quickly.

As we have to provide a "chemistry" explanation, why does this happen?

Answer 1

Speed of electroplating is proportional to current (the number of charges per unit time), so it at first seems that this effect should not depend upon voltage.

However, we can assume that the solution has an approximately constant resistance (R), and from Ohm's law V=IR, we can see that as we increase the voltage (V), current (I) must increase as well.  This is the effect most responsible for the increased rate.

There may be other minor effects as well; the source mentions a need for overvoltage in some cases.  This is when the reaction requires a larger-than-predicted voltage to run at a reasonable rate, so in some cases, higher voltages have a direct effect on the reaction rate.