Klaus Ruppersberg -born in Cologne- has got 24 years of experience of teaching chemistry and biology at different schools and to different types of pupils/ students. Since 2014, he is based at the Leibniz Institute for Science and Mathematics Education at the University of Kiel/ Germany. His main interests are the teaching and learning of complex chemical knowledge and the development of demonstrative and safe experiments. Currently he is working on a special mechanism of a detection reaction for lactose and maltose, i.e. the Woehlk reaction (ammonia) and Fearon's test on methylamine.