When chemical reactions are performed commercially, it is important to
know the relationships between amounts of active species, e.g. how little
reactant is required in a reaction to make a lot of product. The study
of the relationship between the amount of reactants and the amount of product
is called stoichiometry. The stoichiometric amount is the exact amount
of substance required or produced as determined by a balanced chemical
equation. The reactant that determines how much product is formed in a
reaction is called the limiting reagent (or limiting reactant). The maximum
amount of product that can be formed depends on the amount of the limiting
reagent, that reagent depleted first in the reaction. If more of a reagent
is required than available, this reagent is the limiting reagent. If less
of a reagent is required than is available, then this reagent does not
limit the reaction and is said to be in excess.
This program simulates
reactions between two compounds forming one or two products. Four classes
of reactions can be studied: precipitation, combustion, redox, and acid-base.
The mass of products theoretically possible to obtain are calculated based
on the mass of each reactant available and the reaction stoichiometry.
A screen showing the calculations, used to arrive at the displayed results,
is available. Overall, limiting reagents and stoichiometric factors are
essential in the quantitative analysis of chemical reactions.
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INSTRUCTIONS
Select a reaction type by clicking on the Reaction Type Menu and selecting
one of the four reaction types.
Select a specific reaction by clicking on one of the five reaction option
buttons. Only the chemical nature of the reactants are provided; no information
about stoichiometric relationships is given.
Click the "Start Experiment" button to begin an experiment using the selected
reaction.
Add to reactants by clicking on one of the Add buttons, and watch the results
in the bar charts.
Click the "New Experiment" button to select another reaction or reaction
type.