Difference between revisions of "PChem312 f20 w13"

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::- under constant pressure
 
::- under constant pressure
 
::- under constant volume
 
::- under constant volume
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[[File:Screen Shot 2020-11-13 at 7.55.16 AM.png|200px]]
  
 
:6) Liquid --> gas phase change (vaporization/boiling/condensation)
 
:6) Liquid --> gas phase change (vaporization/boiling/condensation)

Revision as of 13:55, 13 November 2020

...return to Chem 312 - home

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Join ZOOM Lab Meeting

Monday, Nov 9, 2020

We will now highlight how to calculate entropy (ΔS) for four processes involving ideal gases:

Screen Shot 2020-11-09 at 8.42.24 AM.png
1) Reversible Isothermal Expansion or Compression
ViTi --> VfTi
Screen Shot 2020-11-11 at 7.31.58 AM.png
2) Constant P, V temperature change
ViTi --> ViTf
PiTi --> PiTf
Screen Shot 2020-11-11 at 7.37.17 AM.png
3) Changes in both V and T, constant P
ViTi -->V fTf
Screen Shot 2020-11-11 at 7.40.27 AM.png
4) Changes in both P and T, constant V
ViTi -->V fTf
Screen Shot 2020-11-11 at 7.47.04 AM.png

Example Problem 1

(Please write out your complete solution and email to bes by next class period)

Consider a gas undergoing the following change under constant pressure (1.00 bar) conditions; calculate the change in entropy (ΔS): Vi = 10.0 L; Ti = 298 K; Tf = 398 K

Example Problem 2

(Please write out your complete solution and email to bes by next class period)

Consider a gas undergoing the following change under constant volume (10.0 L) conditions; calculate the change in entropy (ΔS): Pi = 1.00 bar; Ti = 298 K; Tf = 398 K

Wednesday, Nov 11, 2020

Review contributions to ΔS due to ΔT, ΔV, ΔP for ideal gas/closed system.
Entropy of Phase Changes...

...continuing numbering from above...

5) Solid --> Liquid phase change (fusion/melting/freezing)
- under constant pressure
- under constant volume

Screen Shot 2020-11-13 at 7.55.16 AM.png

6) Liquid --> gas phase change (vaporization/boiling/condensation)
- under constant pressure
- under constant volume

Example Problem 3

(Please write out your complete solution and email to bes by next class period) Poly aromatic hydrocarbons (<-- wiki link here) represent and interesting set of compounds.

PAH.PNG

Calculate the entropy of fusion for 5 PAHs.

Example Problem 4

(Please write out your complete solution and email to bes by next class period) Calculate the entropy of vaporization for methanol, ethanol, and propanol under both constant pressure and constant volume conditions.

Thursday, Nov 12, 2020

LLNL Energy Flow Diagrams website

Cutting Paper

Stepping Stairs
3D words
Folding an Xmas tree
fancy ornament

Friday, Nov 13, 2020