CHEM 1310 Chapter Notes -Thermodynamics, Boiling Point, Standard Molar Entropy

77 views2 pages
Spontaneous vs Nonspontaneous
• Spontaneous
Process or action that continues to
occur without external stimulus once
the action has been started
Reactions do not require constant
input to occur
• Non-spontaneous
Process or action that requires
constant external stimulus to
continue
Reactions require constant input to
occur
• If a process is spontaneous then
the reverse process is nonspontaneous
Entropy (S)
• Is a state function with specified
temperature, pressure and compositions
• Measure of energy at a microscopic
level
Particles may enter into energy levels/states
different ways based upon the amount of
energy in the system
The more energy, the more states partially
filled and the larger the amount of entropy
Based on Boltzmann’s equation (S = k ln W)
and particles-in-a-box
• In general:
Increased T increased entropy
Increased # gas molecules by reaction
increased entropy
Increased disorder/motions increased
entropy
(Practice) Example:
Entropy (S)
• Calculation of entropy
For a reversible reaction:
• A reaction that may change direction with
a very, very small change in some property
For a phase transition:
• Normal boiling point of a non-hydrogen
bonded organic liquid is usually around 87
JK-1mol-1
To relate standard to non-standard:
• Use a variation of the ideal gas law and
Raoult’s law to relate
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Process or action that continues to occur without external stimulus once the action has been started. Reactions do not require constant input to occur: non-spontaneous. Process or action that requires constant external stimulus to continue. Reactions require constant input to occur: if a process is spontaneous then the reverse process is nonspontaneous. Entropy (s: is a state function with specified temperature, pressure and compositions, measure of energy at a microscopic level. Particles may enter into energy levels/states different ways based upon the amount of energy in the system. The more energy, the more states partially filled and the larger the amount of entropy. Based on boltzmann"s equation (s = k ln w) and particles-in-a-box: in general: Increased # gas molecules by reaction increased entropy. For a reversible reaction: a reaction that may change direction with a very, very small change in some property. For a phase transition: normal boiling point of a non-hydrogen bonded organic liquid is usually around 87.

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
Booster Classes
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
Booster Classes