Wednesday, August 1, 2012
A Thermometer of Perturbation
The physics of radiation and understanding the nature of the atom did not consume every scientific imagination at the dawn of the 20th century. Other scientists were busy trying to connect life processes down to the chemical level, rather than trying to build physics up to meet chemistry. The space between physics and biology has always been chemistry's domain.
Other scientists were trying to benefit all of physical science and one prachtig example was J. H. van 't Hoff*, winner of the very first Nobel Prize in Chemistry in 1901. Van 't Hoff's prize citation reads "for his work on the laws of chemical dynamics and also osmotic pressure." What van 't Hoff did was to apply mathematical prowess to chemical equilibria, showing how balances shift when heated.
Van 't Hoff's eponymous equation relates an equilibrium ratio, K, to absolute temperature, showing how chemical reactions shift according to temperature. The law holds for chemistry, physics, biology, geology, meteorology—the whole broad swath—anywhere heat affects chemical balance. In a sense, van 't Hoff quantified Le Chatelier's qualitative principle.
A youthful van 't Hoff also made the visionary proposal that tetrahedral carbon existed and that right and left-handed stereoisomers explained observed optical activity, but he thought it wise to exclude such controversy from his PhD dissertation. Watch this video here: link
*Note the elision of van 't which in Dutch means van het. In German, van het corresponds to von das. Dutch melded the three Germanic genders der, die, and das into just two: de and het.