After the successful STEM intervention for fifth-grade students at the Faculty of Mechanical Engineering and Naval Architecture, it was sixth-graders' turn to visit the Faculty of Chemical Engineering and Technology at the University of Zagreb. Two forms from each experimental school were taken on a tour of three departments – Department of Organic Chemistry, Department of Analytical Chemistry and the Department of Mechanical and Thermal Process Engineering.
In groups of ten, the students went through a myriad of interesting exercises, experiment and demos, with the guidance of the Faculty's professors and teaching assistants. For instance, they changed the color of water into purple, blue, green and yellow by using substances such as Manganese peroxide and adding sugar and alkaline crystals. They also had the task of uncovering a hidden picture drawn with colorless acid and alkali indicators, and is revealed by spraying it with an alkaline solution.
Except from water, the students were also shown how to change the color of flame with the help of ethanol to which different chemical substances are added. Other interesting demos involved the quick dissolution of Styrofoam in acetone, using acetone and dry ice to decrease temperatures below 70 degrees Celsius and create artificial fog, and producing the so-called „elephant's toothpaste“ with the help of hydrogen peroxide, liquid soap and artificial coloring.
At the Department of Analytical Chemistry, students
heard a presentation about Teobroma caccao – the plant responsible for everyone's
favorite sweet indulgence, chocolate. They learned about the step-by-step
procedure used to ascertain the level of iron in chocolate, and how it relates
to different qualities of specific types of the product. There was also talk
about chromatography and how it can be used to discover the colors needed to
produce different shades of felt-tip pens on paper, and make interesting
At the Department for Mechanical and Thermal Process
Engineering, different varieties of crystals, such as snowflakes and salt
crystals, were the main attraction: apart from hearing about them, students were
also given the chance to observe them through microscopes.
During these workshops, students were given the opportunity to get acquainted with Chemistry before its inclusion in their school curriculum, and to see how useful, as well as fun and interesting, it can be.