This document provides an introduction to the subject of chemical thermodynamics. It discusses what thermodynamics is, who studies it, and what it can tell us about chemical reactions and energy transformations. The document also outlines the different approaches to thermodynamics, including classical and statistical thermodynamics. Finally, it lists the four laws of thermodynamics - the zeroth law concerning temperature, the first law regarding conservation of energy, the second law involving spontaneous processes and entropy, and the third law pertaining to absolute entropies and absolute zero.

1. borhan/cmt458/L1borhan/cmt458/L1 11
CMT 458CMT 458
Chemical ThermodynamicsChemical Thermodynamics
BORHANNUDDIN ARIFINBORHANNUDDIN ARIFIN
FSGFSG
borhan545@salam.uitm.edu.myborhan545@salam.uitm.edu.my

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QuoteQuote
““Thermodynamics is a funny subject. TheThermodynamics is a funny subject. The
first time you go through it, you don’tfirst time you go through it, you don’t
understand it at all. The second time youunderstand it at all. The second time you
go through it, you think you understand it,go through it, you think you understand it,
except for one or two small points. Theexcept for one or two small points. The
third time you go through it, you knowthird time you go through it, you know
you don’t understand it, but by that timeyou don’t understand it, but by that time
you are so used to it, it doesn’t bother youyou are so used to it, it doesn’t bother you
anymoreanymore.”.”
-Arnold Sommerfield-Arnold Sommerfield

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What is ThermodynamicsWhat is Thermodynamics??
ThermoThermo =heat,=heat, dynamicsdynamics =power=power
Study of the relation between heat andStudy of the relation between heat and
mechanicsmechanics
Thermodynamics is the branch of scienceThermodynamics is the branch of science
which studies the transformation of energywhich studies the transformation of energy
from one form to another.from one form to another.
Chemical thermodynamics looks at theChemical thermodynamics looks at the
energy transformations which occur as aenergy transformations which occur as a
result of chemical reactions.result of chemical reactions.

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Foundation of subjectFoundation of subject
Foundation of subject based onFoundation of subject based on
many individuals e.g Carnot, Kelvin,many individuals e.g Carnot, Kelvin,
Joule, Mayer, Rankine, Clausius,Joule, Mayer, Rankine, Clausius,
Helmholtz, Gibbs etcHelmholtz, Gibbs etc
In contrast toIn contrast to
MechanicsMechanics NewtonNewton
Electromagnetic theory MaxwellElectromagnetic theory Maxwell
RelativityRelativity EinsteinEinstein

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Who study thermodynamics?Who study thermodynamics?
Who study thermodynamics?Who study thermodynamics?
– Scientists -Chemists, PhysicistScientists -Chemists, Physicist
– EngineersEngineers - Chemical, Mechanical- Chemical, Mechanical
What does thermodynamics tells us?What does thermodynamics tells us?
– Energy changes associated in rxnEnergy changes associated in rxn
(thermochemistry)(thermochemistry)
– Equilibrium positions of reacting systemsEquilibrium positions of reacting systems
– Direction of spontaneous chemical changeDirection of spontaneous chemical change
– Efficiency of heat engines e.g internal combustionEfficiency of heat engines e.g internal combustion
engine, conversion of chemical energy to heatengine, conversion of chemical energy to heat
energyenergy
– Refrigerator as another application of energyRefrigerator as another application of energy
conversion from mechanical energy to heat (cold)conversion from mechanical energy to heat (cold)
energyenergy

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Approaches to ThermodynamicsApproaches to Thermodynamics
Classical ThermodynamicsClassical Thermodynamics
Deals with measurable properties of matter inDeals with measurable properties of matter in
bulk (e.g P,V,T)bulk (e.g P,V,T)
Empirical scienceEmpirical science
Resemble classical mechanicsResemble classical mechanics
Independent of molecular theoryIndependent of molecular theory
Statistical ThermodynamicsStatistical Thermodynamics
Relates properties of individual molecules & theirRelates properties of individual molecules & their
interactions to emp. results of classical therm.interactions to emp. results of classical therm.
Laws of classical and quantum mechanics areLaws of classical and quantum mechanics are
applied to moleculesapplied to molecules

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The laws of thermodynamicsThe laws of thermodynamics
The zeroth law - temperatureThe zeroth law - temperature
The first law – conservation ofThe first law – conservation of
energyenergy
The second law – spontaneousThe second law – spontaneous
process, entropyprocess, entropy
The third law – absolute entropies &The third law – absolute entropies &
attainability of absolute zeroattainability of absolute zero