Conceptual Chemistry

In a recent contribution to ChemEd X "Stoichiometry is Easy", the author states that he has "vacillated over the years between using an algorithmic method, and an inquiry-based approach to teaching stoichiometry. " I would like to suggest that there is another approach to mastering stoichiometry and that it should precede the algorithmic one: it is the conceptual approach based on a particle model to represent the species involved in chemical reactions.

Writing Conversion Factors

This worksheet is intended to be used as a "Guided Instructional Activity" (GIA). Students read a statement that gives a either a conversion factor or a pair of related measures and then write the information as two equivalent fractions ("conversion factors") and as an equality. In each representation, students are directed to give the numeral of the measure, unit, and identity of the chemical.

Finding and Writing the Molar Mass of Elements

This worksheet is intended to be used as a "Guided Instructional Activity" (GIA). It asks students to find the molar mass of selected elements and write the molar mass as two equivalent fractions ("conversion factors") and as an equality. It is designed to help develop good habits in representing molar mass and other conversion factors, and to emphasize the idea that a conversion factor has a numerator and denominator that "name" identical quantities using different measures.

Stoichiometry Fireworks Lab Quiz

Given the amount of one reactant, students must use stoichiometry to find the ideal amount of the second reagent to use to create purple fireworks. The teacher ignites each groups' fireworks. Ideal mixture create little or no ash. Student assignment sheet with directions (and different initial amounts) plus teacher information and sample answers are included. This is an exciting and engaging activity that can be used as a stoichiometry quiz.

Sink or Swim: The Cartesian Diver

In this Activity, students assemble a Cartesian diver and observe the effects of changing the pressure and temperature. An optional extension challenges students to cause the diver to hit the bottom in one minute by connecting the diver bottle to a second bottle in which baking soda and vinegar are reacted.

Fizzy Drinks: Stoichiometry You Can Taste

In this Activity, students make their own version of "Fizzies", a carbonated drink product. Students use different combinations of powdered drink mix, citric acid, baking soda, and water to try to create a good-tasting beverage. The Activity enables students to see the practical benefits of stoichiometry when they use it to develop a product they can immediately consume.

Lego Stoichiometry

In this Activity, students use building-block car kits to explore stoichiometry in a concrete manner. They determine the relationship between the number and mass of each required car component (the pieces in the kit) and the mass of the final product (the completed car). This Activity works well as either an introduction or review of stoichiometry.