A powerful online tool that can enhance practical work

ChemReax screenshot

ChemReaX is a powerful online tool from Science by Simulation with a reaction simulator, a bank of nine exercises, an online titration curve tool and tutorials to help you use the site and explore its content.

My favourite tool on the site is the Acid-Base Titrations section. I use this as part of a flipped lesson when introducing acid-base titration curves. I ask pupils to explore titration curves online before the lesson, then spend time starting to explore more of the mathematics behind pH curves in my lesson. Using it is quite simple, users select the acid or base they are using then the relevant reagents to titrate against it. You can easily adjust the concentrations and volumes added of each reactant before running the reaction and producing the reaction’s pH curve.

A pH curve for the titration of chlorous acid with sodium hydroxide

A pH curve for the titration of chlorous acid with sodium hydroxide

The nine exercises within ChemReaX are all built on google forms and feature multiple choice questions. They explore a number of topics, including limiting reagents, Le Chatelier’s principle and acid-base titrations. The exercises often take ideas from the reaction simulations in the site and ask a wide variety of questions about the results. Once questions are answered, your results are marked and you can see the correct answers. I suggest pupils print out this page and bring it to a lesson so they can receive more detailed support if needed.

To get into the site’s General Reactions section (a reaction simulator), it’s best to use the tutorials. These help explore a variety of different reactions on the site while getting you to think about several different topics including kinetics, equilibria and entropy. Like the rest of the site, these are pitched a little beyond A-level, but more advanced students will love the challenge.

One of the benchmarks for good practical science identified by the recent Gatsby Foundation report by Sir John Holman is titled Real experiments, virtual enhancement. I feel it is a really important point, made clear by the Gatsby report, that while virtual laboratories and online tools are important, they are not there to replace hands-on science but to augment and enhance it. ChemReaX fits this brief well. Users need knowledge of how to carry out the techniques involved, but then can use the site to further their understanding of the topics in their own time.


Peter Banks