When metals are exposed to the open air and bad weather, you might have noticed that they rust. Chemists call rusting corrosion. In this topic we will look at what happens to metal atoms over this time to change them from a “shiny metal” appearance to a dirty, brown powder.
This video shows some examples of objects which have become rusty.
The following experiment can be conducted to demonstrate that water and oxygen are required for rust to occur with iron.
|A||Boiled water + oil layer||No rust. Boiled water has no oxygen and oil stops new oxygen entering.|
|B||Salt water||Severe rust. Salt water is an electrolyte which conducts ions, speeding up rusting.|
|C||Air||Rust. Air and moisture cause normal rusting.|
|D||Air + calcium chloride||No rust. Calcium chloride dries out the air.|
Salt solution acts as an electrolyte, allowing electrons to flow and hence speeding up electron loss.
Therefore we can see that the three conditions required for rust to occur are:
Test out your knowledge of chemistry with Mia Cadaver's chemistry game - it's serious fun!
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.