Gary L. Bertrand
University of Missouri-Rolla


Level 1Level 2Level 3



This program illustrates the stoichiometry of chemical reactions, both graphically and numerically.

Click on "new reaction"
    A window pops up illustrating the initial amounts of the components (A,B,C,D).

Click on "run reaction"
    The window now shows both initial amounts (above the lines) and final amounts (below the lines) of the components.
    The amounts of some components may not change - these are present, but not involved in the chemical reaction (though they may be necessary for the reaction to proceed).

Determine which components are being consumed (reactants) and which are being produced (products).  Click on "quiz" to see if you are right.

Determine the relative changes in the amounts of reactants and products.

Type the reaction which is occurring with reactants to the left of the arrow and products to the right.

Click on "check" to see if your answer is correct.  If your answer is incorrect, a "tutor" button appears.  Click on this to see the correct answer.

Click on "close" to return to the original page.  Click on "new reaction" to generate a new problem or on "go back to reactor" to return to the same problem.

Work through Levels 1, 2, and 3 to make sure that you understand this most basic principle of STOICHIOMETRY.

Level 1:  Starts with zero amounts of products.  One component is completely reacted.

Level 2:  Starts with all components present.  One component is completely reacted.

Level 3:  Starts and ends with all components present (comes to equilibrium).

When you've mastered these, you're ready for more conventional probems beginning with
    Stoichiometry: Self Tests and Tutorials.