June 2010 Entries

Sulphites in the Dishwasher

Have you ever wondered why detergents for automatic dishwashers contain sodium sulphite? It has nothing to do with cleaning dishes. The sulphite protects the dishwasher! Iron reacts with oxygen to form ferric oxide which is better known as rust. This reaction proceeds more readily at high temperatures, as found in washing machines. Where does the oxygen come from? It is dissolved in water. [To read more click on Title.]

Air Bag Chemistry

How can automobile airbags inflate in a few milliseconds? With some clever chemistry! When sodium azide, NaN3, is ignited by a spark, it releases nitrogen gas which can instantly inflate an airbag. The problem, however, is that the reaction also forms sodium metal which reacts with moisture to generate sodium hydroxide, a highly corrosive substance. A burst airbag can therefore wreak havoc. Chemical ingenuity, however, comes to the fore. [To read more click on Title]

Water Intoxication

"Only the dose makes the poison" is the anthem of toxicology. The most innocuous substances can be deadly in high doses. Including water. Believe it or not, there is such a thing as water poisoning. And it can be lethal. If body fluids become excessively diluted, sodium concentrations in the blood drop dramatically. Sodium is an essential mineral in the body and plays a critical role in the transmission of nerve impulses in the brain and in muscles. [To read more click on Title.]

Statistics

I like statistics - at least the ones that make sense. One oft-quoted phrase about these mathematical manipulations is:‘There are lies, damn lies - and statistics’. This has been attributed to Mark Twain, Benjamin Disraeli and Winston Churchill (amongst others), although it seems that Churchill only wished he had coined the remark. Statistics are used by just about everyone... [To read more click on Title.]

Resveratrol Takes a Hit

The two chemicals that have made the headlines the most frequently in the last couple of years are probably bisphenol A and resveratrol. But their fame is due to different reasons. Bisphenol A is usually demonified as the evil substance that leaches out of some plastics and destroys our health, while resveratrol is the compound found in red wine that supposedly increases our life expectancy. [To read more click on Title.]