HS-PS1-7 Mathematical Representations

Fun with Formula Stoichiometry: “Who poisoned Veronica Merriweather?”

"Who Poisoned Veronica Merriweather?" is a fun application of formula stoichiometry for students who are placed in the role of a CSI lab sleuth helping to interpret chemical data to identify a murderer. Topics covered include formula stoichiometry, percentage composition, empirical and molecular formulas and gas chromatography–mass spectrometry.

Does Alka-Seltzer Tell the Truth? A lab activity with a video pre-lab assigment

The lab activity shared here is a simple experiment where students use stoichiometric principles to experimentally determine the amount of sodium bicarbonate in an Alka-Seltzer tablet. Novice students tend to find stoichiometric calculations difficult, so practicing the calculations on a pre-lab assignment boosts their confidence and ultimately leads to more successful labs. The Asynchronous Video Pre-Lab Assignment shared here demonstrates the procedure and the calculations required in the experiment.

The Mole Concept with Krystle Moos

In this ChemBasics Talk, Krystle Moos offers everything necessary to plan a unit on the topic including linked NGSS standards, introductory activities and handouts, manipulative activities, practice problems, links to real world context, a lab and an assortment of videos. Watch the recording and access resources she shared.

The Empirical Formula of Magnesium Oxide Lab: A Successful Failure, Next Steps—and an Important Lesson

Michael Jansen reflects on a very common empirical formula lab that asks students to determine the empirical formula of MgxOy. He then explains how he continues to use it as a "successful failure", how he demonstrates an alternate procedure and leads his students to an important lesson.

Perfecting Mole Conversions

If a student “gets the wrong answer” while performing mole conversions, it can be difficult (for both student and the teacher) to discern where an error was made. Inevitably sometime toward the beginning of learning these conversions, students can become overly confident, plugging numbers in without thinking about whether they are sensical. This card set slows students down to think about the order and purpose of each of the steps in mole conversions.