Questions for Today

.... Finish Chapter 6 .....

1.  Does Nature have a natural direction ?
     "Film clip"
     The Second Law of Thermodynamics

Demonstrations
1.  Melt Ice

Readings
7.1, 7.2, 7.3

OWL Homework
7.1 Homework: Qualitative Entropy

Exam 1 - 7:00 PM , GSMN 51

... No Class .... It's Sadie Hawkins Day

Have a great weekend!
    .... But don't forget to do your OWL homework on Sunday night.....

Questions for Today
1.  What is Entropy ?
     Spontaneous Change

2.  Do some substances have more entropy than others ?
     The Third Law of Thermodynamics - Absolute Entropies
     Thermochemical data - Text .... NIST

3.  How does this work for phase change ?
     Entropy of Phase Change - ΔS^o_phase = ΔH^o_phase / T_phase
     

Demonstrations
1. Red and black balls - shake to separate
  

Readings
7.5, 7.6

OWL Homework
7.2 Homework: Entropy for Phase Change
7.3a Simulation: Second Law of Thermodynamics

Questions for Today
1.  How does this work for phase change ? continued
     Entropy of Phase Change - ΔS^o_phase = ΔH^o_phase / T_phase

2.  Can we predict ΔS for a chemical reaction ?
     Predicting/Calculating ΔS^o_rxn
     More random products, ΔS^o_rxn> 0

3.  Can we predict ΔH^o for a chemical reaction ?
     Combustion - EXOthermic, ΔH^o_rxn< 0
     Make one bond - EXOthermic, ΔH^o_rxn< 0

Demonstrations
1.  Lecture Worksheet 1

Readings
7.2, 7.7

OWL Homework
7.5 Homework: Entropy Change for a Reaction

Questions for Today
1.  What makes a reaction spontaneous ?
      PRS Question

2.  Can we predict the change in Entropy for the surroundings ?
     Predicting/Calculating ΔS_surroundings
 
3.  So we have to look at BOTH entropy and enthalpy ?
      Driving forces for Chemical reactions - Enthalpy and Entropy

Demonstrations
1.  Supersaturated sodium acetate
2.  Lecture Worksheet 1

Have a great weekend
    ....but don't forget to do some chemistry.....

...... Reminder   2 AM ......

Questions for Today
1.  Is there a thermodynamic variable that tells ΔS_universe ?
     Gibbs Free Energy - Putting ΔH_rxn and ΔS_rxn together
     Gibbs-Helmholtz Equation
     ΔG and Temperature

2.  How do we calculate ΔG for a chemical reaction ?
     Standard Gibbs Free Energies of Formation 
     Thermochemical data - Text .... NIST 

3.  How can we understand entropy at the molecular level ?

4.  Can we put this all together ?   
     ....  Equation Summary

5.  Doesn't Life Violate the Second Law of Thermodynamics ?
     Thermodynamics and Biological processes.

Demonstrations
1.  Supersaturated sodium acetate
2.  Barium hydroxide + ammonium nitrate slurry
3.  Lecture Worksheet 2
4.  Unburn sugar ?

OWL Homework
7.6c Homework: Gibbs Free Energy
7.7a Simulation: Free Energy - Temp, dH, dS
7.7c Homework: Gibbs Temperature Calculations
7.8 Homework: Gibbs Free Energy and Work