porcupinetree
not actually a porcupine
- Joined
- Dec 12, 2014
- Messages
- 664
- Gender
- Male
- HSC
- 2015
I've come across some questions about galvanic cells where one of the half cells involves a platinum electrode in an acid solution, with hydrogen gas bubbled over the top of it.
I'm perfectly happy with this scenario if the hydrogen half cell is the oxidation cell: the hydrogen gas oxidises, becoming 2H+ and becoming part of the acid solution.
However, I've seen many examples where this half cell is the reduction cell: hydrogen ions from the acid solution are reduced and then become hydrogen gas. However, in these examples, the bubbling of hydrogen gas over the Pt electrode is still depicted.
Why do we need to bubble extra hydrogen gas over the electrode like this? What purpose does it achieve?
I'm perfectly happy with this scenario if the hydrogen half cell is the oxidation cell: the hydrogen gas oxidises, becoming 2H+ and becoming part of the acid solution.
However, I've seen many examples where this half cell is the reduction cell: hydrogen ions from the acid solution are reduced and then become hydrogen gas. However, in these examples, the bubbling of hydrogen gas over the Pt electrode is still depicted.
Why do we need to bubble extra hydrogen gas over the electrode like this? What purpose does it achieve?