science lesson: what do bleach and hydrogen peroxide have in common?

[quesarah]

I've been posting a bunch of science lessons over in nightxade's journal as checks the chemicals in her household cleaners for potentially hazardous materials. I'm going to repost them here, just 'cause it's science and I love talking about science.

What do bleach and hydrogen peroxide have in common?

Hydrogen peroxide and bleach are both bases, chemical compounds that tend to have high pH. There are "strong" bases and "weak" bases, and these characteristics are related to how easily they shed a part of their structure (called a hydroxyl group) that is very chemically reactive. Once it's been released into solution, the hydroxyl group will raise the pH and catalyze a number of different reactions called "oxidation" reactions. As you can imagine, how corrosive a base is directly relates to how strong the base is.

Bleach is a very strong base and tends to be sold in slightly more concentrated form. Hydrogen peroxide is a weak base and all commercially available solutions are relatively dilute. Both are hazardous, but there are levels of severity.

The same principle about bases also applies to acids, except they shed hydrogen ions instead of hydroxyls. Vinegar is an acid; a weak, dilute acid, but an acid nonetheless. We use a concentrated pure form (acetic acid) in the lab all the time and it's not to be handled carelessly. However, dilute it 50-fold and it's safe to consume.

/end science lesson

Comments

[biogeekgrrl.livejournal.com]

Thanks. The posts make slightly more sense in context of her initial posts but hopefully they're still informative on their own.