What Is That Colorless Solution? A Qualitative Analysis Laboratory for General Chemistry

Abstract

A first-semester general chemistry laboratory experiment for college is described in which students carry out qualitative analysis to identify seven unknown colorless solutions. The experiment serves to correlate qualitative analysis with classification of reactions and can also be used in second-year or advanced-placement (AP) high school chemistry classes.

Visualizing Dissolution, Ion Mobility, and Precipitation through a Low-Cost, Rapid-Reaction Activity Introducing Microscale Precipitation Chemistry

“…Precipitation reactions, historically called double-displacement or even double-decomposition reactions (terms mostly phased out at the university level), have a long history in the classroom and teaching laboratory. − In Alex Johnstone’s 1981 textbook, he described precipitation as occurring when “two ions which make up an insoluble compound come together in solution and settle out as a solid” . Initially, precipitation reactions in the teaching laboratory were conducted in test tubes with a variety of ions, including many that are no longer used because of their toxicity.…”