Unit 3 · 5 lessons
Energy Changes and Rates of Reaction
How much energy a reaction releases or absorbs, how to measure and predict that energy with calorimetry, Hess's law and bond energies, and why some reactions are explosive while others take years.
- 53 practice questions
- 41 flashcards
- 1 interactive lesson
Lessons
- 1Enthalpy Changes and CalorimetrySystem versus surroundings, exothermic and endothermic changes, thermochemical equations, and measuring heat with in a calorimeter to find molar enthalpies.10 questions
- 2Hess's Law and Enthalpies of FormationFinding enthalpy changes you cannot measure directly by combining known equations (Hess's law), by using standard enthalpies of formation, and by estimating from average bond energies.12 questions
- 3Physical, Chemical and Nuclear Energy: Fuels ComparedComparing the energy of phase changes, combustion, fission and fusion per mole and per gram; where nuclear energy comes from (E = mc²); how Ontario's CANDU reactors at Pickering, Bruce and Darlington work; and how to compare fuels by heat of combustion, CO₂ released per kilojoule and power-plant efficiency.11 questions
- 4Rates of Reaction and Collision TheoryMeasuring how fast reactants are used up or products form, relating rates of different species through coefficients, and explaining concentration, temperature, surface area, the nature of reactants and catalysts with collision theory and the Maxwell-Boltzmann distribution.10 questions
- 5Potential Energy Diagrams and MechanismsReading potential energy diagrams for activation energy, the activated complex and enthalpy change; how catalysts lower the energy barrier; reaction mechanisms made of elementary steps, intermediates and a rate-determining step; and how energy changes and catalysts shape energy technologies.Interactive10 questions