Thermodynamics PPT Chemistry Class 11

 Page 1


Chemical Thermodynamics
• The chemistry that deals with energy 
exchange, entropy, and the spontaneity of a 
chemical process.
Page 2


Chemical Thermodynamics
• The chemistry that deals with energy 
exchange, entropy, and the spontaneity of a 
chemical process.
Thermodynamics vs. Kinetics
• Kinetics Domain
? Rate of a reaction 
depends on the 
pathway from 
reactants to products.
• Thermodynamics tells 
us whether a reaction is 
spontaneous based only 
on the properties of 
reactants and products.
Page 3


Chemical Thermodynamics
• The chemistry that deals with energy 
exchange, entropy, and the spontaneity of a 
chemical process.
Thermodynamics vs. Kinetics
• Kinetics Domain
? Rate of a reaction 
depends on the 
pathway from 
reactants to products.
• Thermodynamics tells 
us whether a reaction is 
spontaneous based only 
on the properties of 
reactants and products.
First Law of Thermodynamics
• The change in the internal energy ( DE) of a 
thermodynamic system is equal to the amount 
of heat energy (q) added to or lost by the 
system plus work done (w) on or by the 
system.
DE = q + w
• For work that only involves gas expansion or 
compression, w = -p DV;
Page 4


Chemical Thermodynamics
• The chemistry that deals with energy 
exchange, entropy, and the spontaneity of a 
chemical process.
Thermodynamics vs. Kinetics
• Kinetics Domain
? Rate of a reaction 
depends on the 
pathway from 
reactants to products.
• Thermodynamics tells 
us whether a reaction is 
spontaneous based only 
on the properties of 
reactants and products.
First Law of Thermodynamics
• The change in the internal energy ( DE) of a 
thermodynamic system is equal to the amount 
of heat energy (q) added to or lost by the 
system plus work done (w) on or by the 
system.
DE = q + w
• For work that only involves gas expansion or 
compression, w = -p DV;
Values of Thermodynamic Functions
• FLoT:  DE = q + w;
– q is assigned a positive value if heat is absorbed, 
but a negative value if heat is lost by the system;
– w is assigned a positive value if work is done on, 
but a negative value if work is done by the system.
– For processes that do not involve phase changes, 
positive DE results in temperature increase.
Page 5


Chemical Thermodynamics
• The chemistry that deals with energy 
exchange, entropy, and the spontaneity of a 
chemical process.
Thermodynamics vs. Kinetics
• Kinetics Domain
? Rate of a reaction 
depends on the 
pathway from 
reactants to products.
• Thermodynamics tells 
us whether a reaction is 
spontaneous based only 
on the properties of 
reactants and products.
First Law of Thermodynamics
• The change in the internal energy ( DE) of a 
thermodynamic system is equal to the amount 
of heat energy (q) added to or lost by the 
system plus work done (w) on or by the 
system.
DE = q + w
• For work that only involves gas expansion or 
compression, w = -p DV;
Values of Thermodynamic Functions
• FLoT:  DE = q + w;
– q is assigned a positive value if heat is absorbed, 
but a negative value if heat is lost by the system;
– w is assigned a positive value if work is done on, 
but a negative value if work is done by the system.
– For processes that do not involve phase changes, 
positive DE results in temperature increase.
Spontaneous Processes and Entropy
• Thermodynamics lets us predict whether a 
process will occur but gives no information 
about the amount of time required for the 
process.
• A spontaneous process is one that occurs 
without outside intervention.