0
$\begingroup$

In an electrolytic cell, where the electrolysis of dilute sulfuric acid is taking place, would the rate of electrolysis be constant always, even at the beginning?

By rate of electrolysis, I mean the rate of gas production or the rate of charge delivery. And would this rate be established as soon as I turn on the voltage, or does it slowly increase to a constant level?

$\endgroup$
  • 2
    $\begingroup$ No, no and no. // The rate depends on area of electrodes. So for a given voltage, bigger electrodes have a higher reaction rate. // The instantaneous rate is high because there is no double barrier. // Immediately after the cell starts, a double layer forms and the reaction rate lowers and becomes controlled by diffusion to the electrodes from the bulk solution. $\endgroup$ – MaxW Jul 14 at 15:32
0
$\begingroup$

The rate of electrolysis (decomposition of water) is defined by the current that passes. If you apply a constant voltage, factors arise as suggested in the comment by MaxW.

At constant current, the rate of hydrogen (and oxygen) evolution would be somewhat different initially because on a microscopic level, hydrogen atoms have to cover the surface to some extent to form H2; H atoms may reduce some oxides on the electrode surface, and H2 has to agglomerate to form bubbles (and dissolve in water to saturate it with H2). And then the bubbles have to rise to the surface.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.