Unit 9 - Thermodynamics
PS9- A fundamental rule in nature, and in chemical reactions, is that energy has to be conserved. Most chemical reactions involve some aspect of energy change as reactants are chemically converted to products.
TS 9.1 Enthalpy changes from chemical reactions (as well as physical changes) can be calculated by examining changes in temperature between a system and the surroundings.
9.1.1 Compare changes in internal energy of a system undergoing endothermic and exothermic reactions.
Key Ideas: 1st Law of Thermodynamics, Endothermic, exothermic, heat, temperature, energy diagram, state functions
9.1.2 Calculate the standard enthalpy change of a reaction (DHo) using standard enthalpies of formation (DHfo).
Key Ideas: Thermochemical equations,
9.1.3 Use Hess's Law to determine the enthalpy change of a reaction/change by calculating the sum of multiple reactions with known enthalpy changes.
Key Ideas: Energy cycles, Born-Haber, lattice energy
9.1.4 Calculate standard enthalpy change of a reaction (DHo) using average bond enthalpies (DHbo)
9.1.5 Calculate changes in heat of a system using principles of calorimetry.
Key Ideas: specific heat, DH = mcDT, temperature changes, phase changes, warming/cooling curves
TS9.2 Particle arrangement and freedom of motion describes the order, an quantitative aspect of energy.
9.2.1 Describe entropy changes (DS) in a chemical reaction based on stoichiometric and state changes.
Key Ideas: Second law of thermodynamics, microstates
9.2.2 Predict spontaneity of a chemical process based on changes in Gibb's Free Energy
Key Ideas: DGo = DHo - TDSo, endergonic, exergonic