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Home Concept Builders Thermochemistry Enthalpy Change Directions

Enthalpy Change - Directions

Using the Enthalpy Change Concept Builder is quite simple. There are three difficulty levels in all. Tasks vary per difficulty level. In the first level - Apprentice Difficulty Level - you will be presented with two types of questions. In one type, you will be given the enthalpy change for a particular chemical equation. Four related equations are provided; they will have a different set of coefficients or they will have their reactants and products reversed or both. You have to determine the enthalpy change associated with these equations. You do so by tapping on the Tap Me! button. This pops up a built-in number pad that you can use to enter your answer. Be sure to give attention to the +/- sign. Once you have entered your ∆H answer, you can tap on the Close button or simply tap on a different Tap Me! button to enter the enthalpy change for that reaction. Once you have entered ∆H values for the four chemical equations, a Check Answers button will be visible. If you are satisfied with your answers, tap on the Check Answers button. Your answers will be evaluated and your Progress Report will be updated (if you are a Task Tracker user). The second type of question that appears in the Apprentice Difficulty Level presents three chemical equations and an associated enthalpy change value. You must decide where the energy term would be added in the chemical equation - reactant side or product side. You can add it to (or remove it from) either side by tapping on the Rxt or Prdt buttons. Tapping once adds the energy term; tapping a second time will remove it. Once you have added the energy term to all three chemical equations, a Check Answers button will be visible. If you are satisfied with your answers, tap on the Check Answer button. Your answers will be evaluated and your Progress Report will be updated (if you are a Task Tracker user)

In the second level - Master Difficulty Level- you are given the results of a calorimetry study for a particular reaction - the number of moles of reactant reacted and the quantity of heat (Q) transferred into or out of the system. You must use this information to determine the ∆H value for the given reaction and two other reactions having different coefficients. You enter your answers by tapping on the Tap Me! button. Doing so will pop up our built-in number pad. Use the number pad to enter your three answers. Give attention to the proper +/- sign; the diagram (and words in the problem statement) should help with that. Once you have entered ∆H values for the three chemical equations, a Check Answers button will be visible. If you are satisfied with your answers, tap on the Check Answers button. Your answers will be evaluated and your Progress Report will be updated (if you are a Task Tracker user).

In the third level - Wizard Difficulty Level - you given similar calorimetry results. Only this time you are provided the mass (grams) of reactant reacted and the quantity of heat (Q) transferred into or out of the system. You must use this information to determine the number of moles of reactant and the ∆H value for the given reaction. Use the number pad to enter your answers. Once both answres are entered, you will be able to use the Check Answers button to check your answer.

Your goal is to answer questions, to earn "Stars", and to complete one or more level. Stars are earned when you show success on a particular question. Once you show success on all the questions for a particular activity, you will earn the trophy for that activity.

Concept Builder Teacher Notes