A pyrophoric metal is one that burns spontaneously in oxygen; I came across this phenomenon as a teenager doing experiments at home. Pyrophoric iron for example is prepared by heating anhydrous iron (II) oxalate in a sealed test tube (i.e. to 600° or higher). When the tube is broken open and the contents released, a shower of sparks forms. Not all metals do this; early group metals such as calcium undergo a different reaction releasing carbon monoxide and forming calcium carbonate and not the metal itself. Here as a prelude to the pyrophoric reaction proper, I take a look at this alternative mechanism using calculations.
Posts Tagged ‘Matter’
I analysed the bonding in chlorine trifluoride a few years back in terms of VSEPR theory. I noticed that several searches on this topic which led people to this post also included a query about the differences between it and the bromine analogue. For those who posed this question, here is an equivalent analysis.
This is one of those posts of a molecule whose very structure is interesting enough to merit a picture and a 3D model. The study reports a molecular knot with the remarkable number of eight crossings.
- J.J. Danon, A. Krüger, D.A. Leigh, J. Lemonnier, A.J. Stephens, I.J. Vitorica-Yrezabal, and S.L. Woltering, "Braiding a molecular knot with eight crossings", Science, vol. 355, pp. 159-162, 2017. http://dx.doi.org/10.1126/science.aal1619