Catholic Secondary School Marl
Student Experimentation Internship
Experimental internship at the University of Duisburg-Essen
On November 22nd, 2019, the ninth grade of the KHS Marl went to the University of Duisburg-Essen with 25 students and two teachers. This is already the second visit after the first one last year was very positive. Here, a so-called experimental internship is offered for interested classes from grades 8 to 13. The students at our school are currently working on the topic of "examining soil samples". They were then able to delve deeper into this topic in the experimental internship.
The day began with a 45-minute lecture in which the planned experiments were discussed and the students were divided into groups of two. The experiment was designed so that an unknown soil sample was first examined and then compared with a known one (arable soil, forest soil or topsoil). The sample was first weighed to the nearest 10g and then mixed with 50ml of calcium chloride solution. So that the students did not have to mix the sample themselves, the Erlenmeyer flasks with the mixture were placed on a vibrating plate for 20 minutes. The students used a suction flask and a Büchner funnel for filtering.
The resulting filtrate was then tested for pH, nitrate and phosphate content using test strips.
After the discussion, the students were allowed to carry out the experiments discussed in the university's experimental laboratory. The experimental materials were available for each group so that they could get started straight away. Everyone had to wear the protective clothing required for a laboratory, a lab coat and safety goggles.
The evaluation of the experiments showed that the groups worked so precisely that they were able to deduce the unknown sample from the known sample and classify it correctly.
The subsequent conversation with one of the professors from the Institute of Chemistry Education revealed that he was pleasantly surprised at how cleanly and precisely the groups worked. Nothing was broken and all the experimental materials were cleaned and returned to their designated places.
During the debriefing, the students described the experience in a very positive way. They were proud to be able to conduct research in a university laboratory and use materials that they were not familiar with from school, such as the Büchner funnel. The teachers found the day very pleasant because the students followed all instructions, and they were also proud of the precise and accurate results of the group experiments.
A big thank you goes to Mr Tonyali for the great planning of the visit and to the team of academic staff who actively supported the groups. The KHS wishes them every success in their future studies.
Further information can be found in a video from the University of Duisburg-Essen.
