Difference between revisions of "PChem312 f20 w4"

Revision as of 15:18, 9 September 2020

Monday, Sept 7, 2020

Review: The first Law of thermodynamics: ΔU = q + w

Sec 2.5: Reversible Work, continued

Example Problem 2.1-like

Sec 2.6: Irreversible Work, continued

Example Problem 2.2-like

Sec 2.7: Other Work

focus on electrical work, Example Prob 2.3c

Sec 2.8: State Functions and Path Functions

READ

Wednesday, Sept 9, 2020

Sec 2.9: Comparing Work/Indicator Diagrams

Sorry...still drawing a bunch of diagrams to help clarify the processes...i will send email when complete.

The following shows a PV diagram, also known as an indicator diagram. The center figure is Fig. 2.7 in your text. The outside "cylinders" are my annotation to clarify the diagram. I have separated the "expansion" (irreversible, isothermal) work from the "compression" (irreversible isothermal) work.

Starting at an initial state (P₁, V₁; red dot), when we remove the weight quickly, but do not allow the system to change volume, we find ourselves in a temporary/fictitious state (P₂, V₁; green dot). The irreversible work is then done under P₁ (P₁ < P₂) ending in the final state (P₁, V₂; yellow dot).

Thursday, Sept 10, 2020

- Thermometer (cont.)

Fill thermometer
Calibrate thermometer
Seal thermometer

@@ Line 25: / Line 25: @@
 The following shows a ''PV diagram'', also known as an '''indicator diagram'''. The center figure is Fig. 2.7 in your text. The outside "cylinders" are my annotation to clarify the diagram. I have separated the "expansion" (irreversible, isothermal) work from the "compression" (irreversible isothermal) work.
+:[[File:PV_02_Irrev_IsoT_Exp.png|600px]]
-[[File:PV_02_Irrev_IsoT_Exp.png|600px]]
+::Starting at an initial state (P<sub>1</sub>, V<sub>1</sub>; red dot), when we remove the weight quickly, but do not allow the system to change volume, we find ourselves in a temporary/fictitious state (P<sub>2</sub>, V<sub>1</sub>; green dot). The irreversible work is then done under P<sub>1</sub> (P<sub>1</sub> < P<sub>2</sub>) ending in the final state (P<sub>1</sub>, V<sub>2</sub>; yellow dot).
-:Starting at an initial state (P<sub>1</sub>, V<sub>1</sub>; red dot), when we remove the weight quickly, but do not allow the system to change volume, we find ourselves in a temporary/fictitious state (P<sub>2</sub>, V<sub>1</sub>; green dot). The irreversible work is then done under P<sub>1</sub> (P<sub>1</sub> < P<sub>2</sub>) ending in the final state (P<sub>1</sub>, V<sub>2</sub>; yellow dot).
 ===Thursday, Sept 10, 2020===