Resumen de Exploring the Mysterious Substances, X and Y: Challenging Students’ Thinking on Acid–Base Chemistry and Chemical Equilibrium
Ingo Eilks, Ozcan Gulacar, Jose Sandoval
Acid–base chemistry tends to be one of the more challenging concepts for students to master in the high school and undergraduate chemistry curriculum. Mastery of acid–base chemistry requires a concrete understanding of acid–base theories, chemical equilibrium, electronegativity, periodic trends, and the ability to conceptualize intricate processes at a molecular level. Because of the complex nature of the topic, a combination of effective teaching methods should be used. This paper presents an intriguing acid–base demonstration coupled with a detective story that was designed to aid instructors in engaging students while promoting a conceptual understanding of acids and bases. The selected compounds, X and Y, bring additional value and mystery to the demonstration. X and Y are types of faujasite zeolites, three-dimensional crystalline compounds with various useful chemical properties. Although zeolites are used widely in technology and in everyday products such as laundry detergents, their use in the general chemistry curriculum is surprisingly low. This demonstration provides instructors with the opportunity to cover this important group of compounds and elaborate on the behavior of solid state acids and bases at the same time. As a bonus, this demonstration can also be used to revisit Le Châtelier’s principle of chemical equilibrium in a novel context.
