The developed learning program assumes that the students in
the class have already been exposed to the learning units that
address acid−base and redox reactions. The evolution of O2
through the decomposition of H2O2(aq) has already been
widely addressed in science courses at elementary and junior
high schools. The students should also be familiar with the
evolution of O2 from solid oxygen bleach due to their
encounters with these household chemicals in their daily
lives. However, no students who participated in the educational
practices in this study were aware of the differences between
household liquid and solid oxygen bleaches or of the chemical
concepts utilized to control the reactivity for bleaching