On this day (9th January) in 1868, Danish chemist Søren Sørensen was born. He’s best known for developing the pH scale, which we’ve likely all encountered, to measure the acidity or alkalinity of solutions. This graphic gives a brief overview of the pH scale and what it means.
Sørensen was working at the Carlsberg Research Laboratory — yes, that’s Carlsberg, the beer — when he came up with the pH scale in 1909. It resulted from his work on proteins, during which he noticed that the concentration of hydrogen ions had particularly significant effects. The pH scale gave a simple way of expressing hydrogen ion concentration, and has become a staple of school chemistry.
For more detail on the scale, there’s this previous post.
