LeChatelier's Principle - Directions

Using the LeChatelier's Principle Concept Builder is quite simple. There are three difficulty levels. Every question in the Apprentice and Master Difficulty Levels are very similar. You are presented with the chemical equation for a reversible reaction that is at equilibrium. You are told that a stress to the equilibrium occurs - it might be the addition or removal of reactant or product or it could be an increase or decrease in the pressure or the temperature. You must use he LeChatelier's Principle to decide how the stress will affect the equilibrium position of the system. That is, you must decide whether the equilibrium will shift to the right (in the forward direction), to the left (in the reverse direction), or not shift at all. Tap on the radio button (or on the text to the right of the radio button) to select your answer. The text of the selected answer will be highlighted in red and a Check Answer button will appear. If you change your mind after the first tap, then you can tap a second time to deselect your answer or simply tap on your preferred answer. When you are satisfied with your answer, then you can tap on the Check Answer button. Your answer will be evaluated and your Progress Report will be updated.

In the Wizard Difficulty Level, you have two additional decisions to make. After deciding which direction the equilibrium shifts in response to the stress, you have to decide whether the two specified reactants and/or products will increase, decrease or not change at all. You express your decisions by tapping on a field that toggles through the three choices. After the three choices have been displayed, continued tapping will result in a recylcling of the three answer options. Once you have selected an answer for all three questions, a Check Answer button is displayed. If you are satisfied with your answers, then you can tap on the Check Answer button. Your answer(s) will be evaluated and your Progress Report will be updated.

Your goal is to earn "Stars" and to complete one or more difficulty levels. Stars are earned when you show success on a particular question. If you miss a question then you will have to answer two similar questions correctly before earning a star. Once you show success on all the questions for a particular difficulty level, you will earn the trophy for that difficulty level.