Most chemical reactions are reversible, i.e. while reactants form products, the reverse reaction occurs simultaneously with products yielding starting materials. In a closed system it is possible to reach equilibrium, a point at which the rates of formation of products and reactants are equal. Various factors including temperature, volume, pressure, and reactant or product concentration, however, affect the degree to which reactions take place. Le Chatelier's principle predicts the effects of changes in these factors on the point at which equilibrium for a reaction is reached. By definition, Le Chatelier's principle states that a change in any outside factor influencing an equilibrium will cause the system to adjust to counteract or minimize the effect of the change. For example, if a solution of a gas in a liquid is heated, according to Le Chatelier's principle, the equilibrium shifts in an attempt to absorb a quantity of the added heat energy.
This module explanes Le Chatelier's Principle qualitatively and allows the user to manipulate a reaction and see the effects on the equilibrium system.
INSTRUCTIONS
1. Select a reaction to be stressed from the Reaction menu.
2. Choose which property to vary by highlighting one of the five properties from the list box.
3. Select the way to apply the property by selecting one of the application option buttons.
4. Click on the Run button to apply the variable and find the resultant reaction and change to the equilibrium mixture after the reaction is varied.
