Unit 8 Thermodynamics & Gibbs
SEE BELOW FOR VIDEO TUTORIALS ON HOW TO USE/APPLY HESS'S LAW! Scroll to the bottom half for info for Tuesday's quiz (MAY 16).
Learning objectives:
Define enthalpy and entropy and describe the relationship between them.
Describe at the molecular (or atomic) level three different ways heat is transferred.
Compare and contrast endothermic and exothermic reactions in terms of energy.
Calculate the enthalpy change in a system.
Use bond energies for reactants and products in a chemical reaction to determine if a reaction is exothermic or endothermic (aka - calculate the enthalpy of a reaction)
Watch this video to review how:
Where do bond energy values come from: (Also explains the relationship between bond length and bond energy)
STUDY THIS PICTURE TO REMEMBER THE RELATIONSHIPS BETWEEN THESE VALUES:
OTHER VIDEOS FOR THIS UNIT:
Hydrogen Cars: https://www.youtube.com/watch?v=JA4TYSST2I4
How fuel cell vehicles work: https://www.youtube.com/watch?v=tajigZ2e6tQ
Understand our labs a little better with this video on Calorimetry:
CALCULATING ENTHALPY USING MANY STEPS:
USING GIBB'S FREE ENERGY EQUATION:
Learning Target for next quiz: May 16th
Use the equation to calculate Gibb's Free energy and determine if a reaction is going to occur spontaneously or not.
Describe how entropy and enthalpy values can help you predict the spontaneity of a reaction (know which one is H and which is S).
Describe how an increase in temperature can actually cause a chemical reaction to stop!
State the general rules of the first two laws of Thermodynamics (watch this video link: https://www.youtube.com/watch?v=8N1BxHgsoOw
What is this equation and how is it used? Watch this short Bozeman Science video for the run-down or for review:
Now look at how you actually use Gibb's free energy: