Chemistry and Oxidation States

We all comprehend rust when we see it, but how many of us grasp the fascinating process of oxidation? The oxidation state, in chemistry, is how oxidized an atom is in a chemical compound. The oxidation state is a number which is determined by a few rules:

1) A pure substance made up of only one element has an oxidation state of zero. For example, chlorine exists naturally as Cl2. and has an oxidation number of zero.

2) An ion, which is an atom without any of its electrons, has an oxidation state equal to its electric charge. For example, a lithium ion has a charge of +3.

3) In most compounds, oxygen and hydrogen have oxidation states of -2 and +1, respectively.

4) Removal of oxygen, the root cause of rust, is called reduction.

Well, we could continue on and on, but the point is, oxidation science is well understood, as is the science of rust removal. A good rust remover is one that eliminates any rust it contacts. A good rust remover will clean a hunk of metal with a soaking that lasts from half an hour to 12 hours, depending upon the oxidation state of the part.

You'll know the part is clean when its shines brilliantly after treatment. An excellent cleaner removes oxygen from all common metallic compounds, which is a process called reduction. A properly cleaned part is reduced by an effective cleaner, dissolving away years of accumulated rust. Also, a cleanser should never harm non-metallic materials such as plastic or rubber.

The reduction of oxidation state has important economic implications. Imagine a rusty cast-iron fry pan. You might replace it for a hundred dollars or even more. Or, for the price of a container of rest remover, you can clean the pan and make it as good as new. It's the miracle of chemistry!

Restoring a frypan is spare change compared to how much money you can save by applying a specially-engineered rust remover to costly items like car parts. Another example: expensive hand tools like hand planes and chisels would be gut-wrenching to discard because of rust. Fortunately, science understands how to reverse oxidation quickly and without causing damage. And like a magic trick, you can reuse left-over rust remover again and again until it is exhausted. Science is truly awesome!