This document provides an overview of the key concepts covered in 5 sections of a chapter on energy and chemical change: Section 15.1 defines energy and distinguishes between potential and kinetic energy. It relates chemical potential energy to heat released or absorbed in chemical reactions. Section 15.2 describes how calorimetry is used to measure energy changes and defines enthalpy and enthalpy changes. Section 15.3 explains how to write thermochemical equations and describes energy changes during state changes. Section 15.4 discusses calculating enthalpy changes using Hess's law and standard enthalpies of formation. Section 15.5 differentiates between spontaneous and nonspontaneous processes and explains how entropy

2. Chapter Menu Energy and Chemical Change Section 15.1 Energy Section 15.2 Heat Section 15.3 Thermochemical Equations Section 15.4 Calculating Enthalpy Change Section 15.5 Reaction Spontaneity Exit Click a hyperlink or folder tab to view the corresponding slides.

4. Section 15-1 Section 15.1 Energy (cont.) energy law of conservation of energy chemical potential energy heat calorie joule specific heat Energy can change form and flow, but it is always conserved.

9. Section 15-1 Measuring Heat (cont.)

14. End of Section 15-1

16. Section 15-2 Section 15.2 Heat (cont.) calorimeter thermochemistry system surroundings The enthalpy change for a reaction is the enthalpy of the products minus the enthalpy of the reactants. universe enthalpy enthalpy (heat) of reaction

22. Section 15-2 Chemical Energy and the Universe (cont.)

23. Section 15-2 Chemical Energy and the Universe (cont.)

26. End of Section 15-2

28. Section 15-3 Section 15.3 Thermochemical Equations (cont.) thermochemical equation enthalpy (heat) of combustion molar enthalpy (heat) of vaporization molar enthalpy (heat) of fusion Thermochemical equations express the amount of heat released or absorbed by chemical reactions.

30. Section 15-3 Writing Thermochemical Equations (cont.)

32. Section 15-3 Changes of State (cont.)

33. Section 15-3 Changes of State (cont.)

37. End of Section 15-3

39. Section 15-4 Section 15.4 Calculating Enthalpy Change (cont.) Hess’s law standard enthalpy (heat) of formation The enthalpy change for a reaction can be calculated using Hess’s law.

41. Section 15-4 Hess's Law (cont.)

44. Section 15-4 Standard Enthalpy (Heat) of Formation (cont.)

46. Section 15-4 Standard Enthalpy (Heat) of Formation (cont.)

49. End of Section 15-4

51. Section 15-5 Section 15.5 Reaction Spontaneity (cont.) spontaneous process entropy second law of thermodynamics free energy Changes in enthalpy and entropy determine whether a process is spontaneous.

63. End of Section 15-5

64. Resources Menu Chemistry Online Study Guide Chapter Assessment Standardized Test Practice Image Bank Concepts in Motion

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81. IB 1

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95. CIM Figure 15.5 Calorimetry Figure 15.10 Heat Flow in Endothermic and Exothermic Reactions Table 15.6 Reaction Spontaneity

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