# How is the current density solved for in an electrolyzer unit?

Shan43
Hydrogen production rate is typically measured in current density, but what is the area in which the current is divided by to find such a value?

## Answers and Replies

Mentor
Hydrogen production rate is typically measured in current density, but what is the area in which the current is divided by to find such a value?
Maybe the cross-sectional area of the electrolyte in the reaction volume of the electrolysis apparatus? Can you post some links to what you have been reading about electrolysis to help us understand your question better?

https://en.wikipedia.org/wiki/Electrolysis

Mentor
Electrode surface.

Science Advisor
Homework Helper
Gold Member
Tafel plot?

Shan43
Maybe the cross-sectional area of the electrolyte in the reaction volume of the electrolysis apparatus? Can you post some links to what you have been reading about electrolysis to help us understand your question better?

https://en.wikipedia.org/wiki/Electrolysis

View attachment 295166
Well this wasn't based off of much reading per say, but for context I'm talking about an alkaline electrolyzer where a battery (9V battery that alligator clips can attatch to) serves as a power source and wires connect to an ammeter which would then connect to an electrode. The charge will flow through the electrolyte solution to other electrode which connects through a wire back to the battery on the negative end. What would the area the current should be divided by in this context?

Sorry for the late reply btw

Mentor
The charge will flow through the electrolyte solution to other electrode which connects through a wire back to the battery on the negative end. What would the area the current should be divided by in this context?
It seems like Borek's reply applies Occam's Razor:
Electrode surface.

Shan43
It seems like Borek's reply applies Occam's Razor:
Ok, thank you guys very much!

berkeman