AP Chemistry · Summary

Unit 6 summary

  1. Heat flows from warmer to cooler until both reach the same temperature; heat lost by one part equals heat gained by the other.
  2. q = mcΔT with ΔT = final − initial; during a phase change, q = n × ΔH of the change and the temperature stays constant.
  3. In a calorimeter, qreaction=−qsolutionq_{\text{reaction}} = -q_{\text{solution}}: water that warms means an exothermic reaction with ΔH < 0.
  4. ΔH belongs to the equation as written: multiply the equation and you multiply ΔH; reverse it and you change the sign.
  5. Find heat from a mass with grams → moles → (ΔH ÷ coefficient); the limiting reactant sets the heat.
  6. ΔH° = Σ n ΔH°f(products) − Σ n ΔH°f(reactants), with elements in their standard states at zero.
  7. From bond energies, ΔH ≈ bonds broken − bonds formed; a reaction is exothermic when forming bonds releases more than breaking bonds absorbs.