Chem_215_Lect_20_Color

Chem_215_Lect_20_Color - PS 6 Due Friday Prelim 1 Handed...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
1 PS 6 Due Friday Prelim 1 Handed Back Last Friday
Background image of page 1

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

View Full DocumentRight Arrow Icon
2 The Concept of Entropy (S) Entropy is proportional to the number of microstates corresponding to a given state (including position and energy) S = k ln Ω Ω = the number of microstates accessible to system k = Boltzmann constant = R/N A
Background image of page 2
3 Δ S is based on two measurable quantities: q rev = heat absorbed by system in a reversible process T = temperature of system in Kelvin T S , Change ntropy E rev q = Δ A reversible expansion process: - “infinitesimally small” grains of sand are removed one at a time. - adding one grain at any time would reverse process.
Background image of page 3

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

View Full DocumentRight Arrow Icon
4 Entropy Changes in Phase Transitions (Note: vaporization is essentially reversible at normal boiling point) The enthalpy of vaporization of water is 40.7 kJ/mol at 100 o C. What is the molar entropy of vaporization of water at 100 o C? H 2 O (l, 1 atm) H 2 O (g, 1 atm) Δ S vap = Δ H vap /T vap
Background image of page 4
5 Second Law of Thermodynamics In a spontaneous process, the entropy of the universe increases: Δ S universe = Δ S
Background image of page 5

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

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/05/2009 for the course CHEM 2150 taught by Professor Chirik,p during the Fall '08 term at Cornell.

Page1 / 9

Chem_215_Lect_20_Color - PS 6 Due Friday Prelim 1 Handed...

This preview shows document pages 1 - 6. Sign up to view the full document.

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