chemical equilibrium endothermic reactions Energy exothermic reactions thermodynamics
Age Group
16 17
Expected time
3 periods
The disappearing lab report.PDF
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The disappearing laboratory report

What’s the mystery? This mystery deals with a laboratory report in which the written results suddenly vanished. The students need to find out how the writing vanished, how to recover the vanished data, and what the secret of the pen is.
Domain(s) Chemistry
Subdomain keywords Energy (exothermic and endothermic reactions), chemical equilibrium, thermodynamics.
Age group 16 to 17 years old.
Expected time for the mystery Approximate time for teacher preparation: one hour to prepare the lab reports (writing them and warming them up to make the ink disappear). If not, pens are available: time needs to be allocated to purchasing the pens.Approximate time in classroom: up to six periods of 45 min each: one period to engage and explore, one to explain, three for open enquiry, and one to present the enquiry in class.
Safety/supervision None. If there is use of liquid nitrogen, the safety regulations related to its use are necessary.Disclaimer: the authors of this teaching material will not be held responsible for any injury or damage to persons or properties that might occur in its use.
Preparation and list of materials
  • A pilot friXion ball erasable ink pen for each group of three to four students.
  • A lab report with missing/erased data.
  • Different equipment to heat and cool the paper (such as a kettle, hair dryer, or liquid nitrogen).
Learning objectives Exposing students to reversible chemical reactions. Experimenting with the conditions that influence such reactions.
Resources More on the phenomenon can be found at the following website: