F09_230_L07pre - CHEM 230 F09 Lecture 7 Chapter 6...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEM 230 F09 Lecture 7 Chapter 6: Thermodynamics First Law Session ID: 230
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Thermodynamics = study of energy consevation Work free expansion (no work done against a vacuum) no volume change w =0 irreversible: w = -P V work at constant pressure reversible: w = -nRTln(V 2 /V 1 ) *constant temperature *allows you to find maximum work at changing pressure First Law Surroundings, Systems, Exchanges Heat signs, units (cal) Enthalpy Heat Capacity
Background image of page 2
Energy exchanges Internal Energy (of a system) = U Measure U from perspective of the system. + U = gain energy of system - U = loss of energy from system
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
First Law The internal energy (U) of an isolated system is constant. U = q +w Energy is a state function -it depends only on the state and not how it got there (so are T, P, V) Energy as work (w) Energy as heat (q)
Background image of page 4
Concept Question Hiker #1 and Hiker #2 start from the same point on a hill, but take different paths down to the 100 m marker. Hiker #1 takes a path that is 200 m long. Hiker #2 takes a path that is 300 m long. Which of the following would not be a state function? A. Their mass B. The height they climbed C. The force of gravity, g D. The distance they walked E. None of the above
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
First Law For all systems and surroundings, the heat from or work done on the system is the opposite of the heat from or work done on the surroundings: q surroundings = -q system w surroundings = -w system In a reversible system, maximum work performed In an irreversible system, some work performed http://www.chem1.com/acad/webtext/thermeq/TE2.html#1C
Background image of page 6
Two identical engines of the same consume the same quantity of energy. After 10 minutes they are stopped and the temperature of the oil is taken. The oil from engine #1 is 80 o C. The oil from engine #2 is 90 o C. Which engine is performing more work? A. Engine #1
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/29/2010 for the course CHEMISTRY 230 taught by Professor Gottfried during the Fall '10 term at University of Michigan.

Page1 / 32

F09_230_L07pre - CHEM 230 F09 Lecture 7 Chapter 6...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online