Thermochem

• What does thermochemistry focus on?

  Energy concepts, heat transfer, and enthalpy changes
• What is the law of conservation of energy?

  Energy cannot be created or destroyed
• How is heat defined in thermochemistry?

  Energy transfer due to temperature differences
• What are exothermic reactions?

  Reactions that release heat to surroundings
• What are endothermic reactions?

  Reactions that absorb heat from surroundings
• What does enthalpy (ΔH) measure?

  Heat flow at constant pressure
• What is calorimetry used for?

  Measuring heat changes in reactions
• What is specific heat capacity?

  Heat required to raise temperature of substance
• What is molar heat capacity?

  Heat required to raise temperature of one mole
• How does Hess’s law apply in thermochemistry?

  Total enthalpy change equals sum of steps
• What are standard enthalpies of formation?

  Enthalpy changes for forming one mole of compound
• What is the difference between temperature and heat?

  Temperature measures average kinetic energy
• How does calorimetry work?

  Measures heat exchanged by temperature change
• What is the fundamental equation of calorimetry?

  $Q_{system} =$$-Q_{surrounding}$
• How do you calculate ΔH for a reaction?

  $ΔH =$$H(products) - H(reactants)$
• What happens to ΔH when a reaction is reversed?

  Change the sign of ΔH
• What happens to ΔH when coefficients are multiplied?

  Multiply ΔH by that integer
• What are the types of energy relevant to thermochemistry?

  • Potential Energy: due to position/composition
  • Kinetic Energy: due to motion of objects
• What are the setups used in calorimetry?

  • Constant-pressure calorimeter (coffee cup)
  • Constant-volume calorimeter (bomb calorimeter)
• What are the practical applications of thermochemistry?

  • Calculate energy changes for phase transformations
  • Analyze heating curves, bond energies, and reaction enthalpies
• What are the key insights from thermochemistry?

  • Focus on energy transfer, especially heat
  • Distinction between potential and kinetic energy
  • Importance of calorimetry and Hess's law