Özet:

This paper presents results on improvement of college students’ knowledge of “units of measurements” understanding and their inter-conversions, and improving their skills in manipulating and understanding chemical calculations through practical experiments on corrosion of four different steel alloys. The experiments constitute a practical part (1 hour/week) of a course on materials and corrosion for second year diploma program in chemical processing. The course includes 3 hours theory as the major part. The course introduced learners to the physical and mechanical properties of materials commonly used in the chemical processing industries. One part of the course examines the factors that promote the corrosion of these materials when used in industrial processes. Learners also examine a variety of means of controlling and monitoring of corrosion and corrosion processes in chemical industries.   During the academic term winter 2017, 20 students were enrolled in this course. Due to the limited time allotted to practical session, the practical part of the course was focusing on a long single experiment of monitoring corrosion rate of four bars of different steel alloys having the same surface area, placed in a solution of 3.5 % sodium chloride solution, over 8 weeks, by measuring weekly weight loss of each specimen. Students’ development of knowledge was monitored by three different theoretical tests, over the period, that involve similar calculations (but not identical) on rust and rate of corrosion. The first two tests were undertaken independent of the final results of the practical part with similar questions (but not identical) were given. The third test was undertaken after the students have submitted reports of their results and calculation.  In the first test, two students only were able to score over 80% of the mark in the calculation part of the test which consists of two problems; four were able to solve one problem only scoring about 50%. Fourteen students were unable to solve any of the two problems. In the second test, four students scored over 80% of the mark in the calculation part and 7 students scored around 50%. The rest failed to solve any problem. In the third test 19 students scored over 80% and 1 student scored 50%.      On the units of measurement that required 3 conversions, 2 students were able to manipulate all the conversion calculation correctly, 5 with two correct conversions, 13 with no correct conversion.  In the second test 8 students were able to manipulate all conversions correctly (although some included few calculation error), 4 with two correct conversions and 8 with no correct conversions. In the third test 18 students were able to manipulate all conversions correctly, 2 students with two correct conversions.  

Anahtar Kelimeler: