The explosive power of nitration

An image showing the Oppau explosion

Source: © Sueddeutsche Zeitung Photo/Alamy Stock Photo

A violent but vital reaction

About once a month, a report of an accident in a chemistry laboratory will populate a Google News alert that I have set. The cause is typically the same: nitric acid in a waste container, that someone unintentionally adds in some acetone rinse waste or other organic solvent to, creating an explosion that destroys a hood. It’s a demonstration of the power of concentrated nitric acid as a reactant – one that chemists routinely use to add a nitrogen into their molecule and one that industry harnesses for chemical processes.

It is difficult to overestimate the history and importance of nitration to both modern life and chemistry itself. The Nobel prizes came from the fortune of Alfred Nobel, who stabilised nitroglycerin in diatomaceous earth to make dynamite; nitroglycerin is made from the reaction of nitric acid and glycerol. You can’t just use any nitric acid, like the concentrated nitric acid that you have in your lab in the bottle with the red cap. Rather, you have to use ‘white fuming nitric acid’, which contains 95% nitric acid and doesn’t have any yellow or brown nitrogen oxides.