AP Chemistry: Class 22

Period E – Wednesday, October 8th

Problem Solving in Thermodynamics

• review homework
• questions?

Enthalpy and Chemical Processes

• Q = DH (@ constant pressure)
• So, enthalpy is relatively easy to discuss and measure
• DH for any process
  • boiling, evaporation, dissolving
  • chemical reaction
• It is the energy associated
  • can link to mole ratios
  • linkage to stoichiometry powerful
  • can add DH for reactions together
• Suggested Practice
  • Ch. 5 (62, 65, 66, 73)

Lab Tomorrow

• prep lab (Hess’s Law) in the LNB
• complete lab on Thursday
• calcs, analysis, conclusion in LNB for following Thursday

Homework

• Note: Exam for Chapter 5 next Friday
• Prep Lab in LNB
• Buy & Install: Sparkvue HD
• Download Google Drive app and link to Soxteacher sahred documents

LAB ANSWER

You cannot determine the identity of the carbonate because the calcium chloride is the limiting reactant in the reaction. Gravimetric analysis only works when the precipitate is tied to the desired limiting reactant.