The phrase refers to prepared documents designed to reinforce understanding of pH concepts through application. These documents often contain a series of problems or exercises requiring the learner to calculate pH, pOH, hydrogen ion concentration, or hydroxide ion concentration, typically accompanied by the correct solutions for self-assessment.
The availability of these resources is critical for students learning about acids, bases, and equilibrium. They provide a structured way to test comprehension, identify areas needing further study, and build confidence in applying theoretical knowledge to practical scenarios. Their use can be traced back to the increasing emphasis on quantitative reasoning in chemistry education.