The 9 bottle problem is a classical lab job in high school and college chemistry. In solving this chemical "crossword" puzzle, students will be forced to integrate the knowledge acquired on a great variety of items such as solubility and colors of common inorganic precipitates, the possible evolution of gases, acid-base properties of salts, formation of metal-ion complexes, acid-base reactions, and oxidation-reduction reactions, including the influence of pH on them.A free copy of the program and the teacher guide, in Spanish, are available from the authors upon request.
Baggio, S., & Harvey, M. A. (2015). El problema de los 9 frascos: Un clásico de laboratorio para alumnos de química básica, simulado en computadora. Educacion Quimica, 26(4), 281–287. https://doi.org/10.1016/j.eq.2015.05.010