Energy

Class Notes
Energy

Course Content
__6 - Intramolecular Bonding__ 6.B - As atoms bond, energy is released to the surroundings resulting in a system with lower energy __ 15 - Calorimetry __ 15.A - Potential energy is in the form of chemical energy and kinetic energy is in the form of thermal energy. The total amount of chemical energy and/or thermal energy in a system is impossible to measure. 15.B - Thermal energy is the energy of a system due to the movement (translational, vibrational and rotational) of its particles. 15.C - The thermal energy of an object depends upon the amount of matter present (mass), temperature and chemical composition. 15.D - Conservation of energy is an important component of calorimetry equations. The energy change of a system can be calculated from measurements (mass and change in temperature) from calorimetry experiments in the laboratory 15.E - Specific heat is a measure of how much energy is needed to change the temperature of a specific mass of material a specific amount. 15.F - Some materials require little energy to change their temperature and other materials require a great deal to change their temperature by the same amount. 15.G - Specific heat values can be used to calculate the thermal energy change, the temperature (initial, final or change in) or mass of a material in calorimetry. __ 16 - Energy in Reactions __ 16.A - Energy in reactions involves valence electrons forming bonds to yield more stable products with lower energies. 16.B - Energy is required to break interactions and bonds between the reactant atoms and energy is released when an interaction or bond is formed between the atoms in the products. 16.C - Generally, energy is transferred out of the system (exothermic) when the products have stronger bonds than the reactants and is transferred into the system (endothermic) when the reactants have stronger bonds than the products. Molecules with weak bonds (e.g., ATP) are less stable and tend to react to produce more stable products, releasing energy in the process. 16.D - Predictions of the energy requirements (endothermic or exothermic) of a reaction can be made given a table of bond energies. 16.E - Graphic representations can be drawn and interpreted to represent the energy changes during a reaction, including the activation energy. 16.F - The roles of energy and entropy in determining the spontaneity of chemical reactions are dealt with conceptually in this course.

Practice Problems
Energy and Calorimetry: page 353 - #24-28 Hess's Law: page 354 - #32-35