What are some examples of electrochemical processes?

1 Answer
Dec 17, 2014

Galvanic cells are a great example of an electrochemical process.

![chemwiki.ucdavis.edu)

The galvanic cell has the capability of deriving electrical energy from spontaneous REDOX reactions that take place within the cell. The cell consists of two different metals connected together by a salt bridge.

Electrons will always flow from the oxidation half cell (the anode) to the reduction half cell (the cathode) - in other words, from the more negative half reaction to the more positive half reaction.

Another great example of an electrochemical process is corrosion. A piece of bare iron will rust quickly when exposed to moisture, the corrosion rate being enhanced by an electrochemical process in which a water droplet becomes a miniature galvanic cell in contact with the metal (it oxidizes the iron).

![hyperphysics.phy-astr.gsu.edu)

Iron supplies electrons at the edge of the droplet to reduce oxygen from the air - the iron surface inside the droplet acts as the anode for the process

Fe(s)Fe2+(s)+2e

The electrons move through the iron to the outside of the water droplet, where

O2(g)+2H2O(l)+4e4OH(aq)

The hydroxide ions now react with the iron ions to form iron (III) hydroxide (a precipitate)

Fe2+(aq)+2OH(aq)Fe(OH)2(s)

Rust is then produced by the oxidation of the precipitate

4Fe(OH)2(s)+O2(g)2Fe2O3H2O(s)+2H2O(l)

Here's a video of electrochemical machines, another example of REDOX reactions applications

and a video on corrosion