The Making of a Solution: A Simple but Poorly Understood Concept in General Chemistry

A primary goal in many general chemistry laboratories is to teach students to properly perform dilutions and make solutions. This article presents a simple exercise to test if your students have acquired this ability from their introductory laboratory exercises. Our results indicate that approximately 50% of the students cannot perform this task on their first attempt, but with guidance and additional attempts their success rate improves. Approximately 30% of the students still fail at this task after additional attempts, but this exercise does improve the laboratory technique of all students. Students used a variety of dilution strategies to achieve the same final concentration; but the most common strategy used by the students was the one deemed most logical by the professors.