Applied Chemistry
Engr. Shakeel Ahmad
Introduction,
History and
Applications

1. Introduction
Thermodynamics is a branch of physics that deals
with heat, work, and temperature, and their relation
to energy, radiation, and physical properties of matter. The
behavior of these quantities is governed by the four laws of
thermodynamics which convey a quantitative description
using measurable macroscopic physical quantities, but may
be explained in terms of microscopic constituents
by statistical mechanics. Thermodynamics applies to a
wide variety of topics in science and engineering,
especially physical chemistry, biochemistry, chemical
engineering and mechanical engineering, but also in other
complex fields such as meteorology.

2. Introduction
Thermodynamics is a science and, more importantly,
an engineering tool used to describe processes that
involve changes in temperature, transformation of
energy, and the relationships between heat and work.
It can be regarded as a generalization of an enormous
body of empirical evidence. It is extremely general:
there are no hypotheses made concerning the
structure and type of matter that we deal with. It is
used to describe the performance of propulsion
systems, power generation systems, and refrigerators,
and to describe fluid flow, combustion, and many
other phenomena

3. Introduction
The focus of thermodynamics in aerospace engineering is on the
production of work, often in the form of kinetic energy (for
example in the exhaust of a jet engine) or shaft power, from
different sources of heat. For the most part the heat will be the
result of combustion processes, but this is not always the case.
The course content can be viewed in terms of a ``propulsion
chain'' as shown in Figure, where we see a progression from an
energy source to useful propulsive work (thrust power of a jet
engine).

History- Before 1800
 OTTO VON GUERICKE
His major scientific achievements were the establishment of
the physics of vacuums, the discovery of an experimental
method for clearly demonstrating electrostatic repulsion,
and his advocacy of the reality of "action at a distance" and
of "absolute space“
 R O B E R T B O Y L E
Founders of modern chemistry, and one of the pioneers of
modern experimental scientific method. He is best known
for Boyle's law, which describes the inversely proportional
relationship between the absolute pressure and volume of a
gas, if the temperature is kept constant within a closed
system

History- Before 1800
 THOMAS SAVERAY
He is famous for his invention of the first commercially used steam
powered engine
 GUILLAURNE AMANTONS
He came close to finding absolute zero. Absolute zero is the lower
limit of the thermodynamic temperature scale, a state at which
the enthalpy and entropy of a cooled ideal gas reaches its
minimum value, taken as 0.
 JOSEPH BLACK
Introduced term Latent Heat (Latent heat is energy released or
absorbed, by a body or a thermodynamic system, during a
constant temperature process) and specific heat (The specific
heat is the amount of heat per unit mass required to raise the
temperature by one degree Celsius)

History,1800-1847
 JOHN LESLIE
Sir John Leslie observes that, black surface radiates heat more
effectively than a polished surface, suggesting the importance of
black body radiation.
 ROBERT BROWN
He introduced a word Brownian Motion. Brownian motion is the
random motion of particles suspended in a fluid (a liquid or a
gas) resulting from their collision with the quick atoms or
molecules in the gas or liquid.
 JOSEPH LOSSAC
Gay-Lussac first formulated the law, Gay-Lussac's Law, stating that
“if the mass and volume of a gas are held constant then gas
pressure increases linearly as the temperature rises

History, 1800-1847
 EMILE CLAPEYRON
Emile Clapeyron popularises Carnot's work through a
graphical and analytic formulation. He also combined
Boyle's Law, Charles's Law, and Gay-Lussac's Law to
produce a Combined Gas Law PV/T = k.
 HENRI VICTOR
Henri Victor Regnault added Avogadro's Law to the
Combined Gas Law to produce the Ideal Gas Law PV =
nRT

History, 1847-1948
 WILLIUM RANKINE
Introduce thermodynamic function, later identified as entropy (a
measure of the number of specific ways in which a thermodynamic
system may be arranged, commonly understood as a measure of
disorder )
 RUDOLPH CLAUSIUS
Central founders of the science of thermodynamics. By his restatement of
Sadi Carnot's principle known as the Carnot cycle, he put the theory of
heat
 VAN DER WAAL
Well known due to van der Waal's equation (this equation is the sum of
the attractive or repulsive forces between molecules (or between parts
of the same molecule) other than those due to covalent bonds, or the
electrostatic interaction of ions with one another, with neutral
molecules, or with charged molecules).

History, 1847-1948
 HENRY LOUIS
He is well known by his principle called as L E CH AT LI E R’ S P RIN CI P
L E ( When a system at equilibrium is subjected to change in
concentration, temperature, volume, or pressure, then the system re-
adjusts itself to (partially) counteract the effect of the applied change
and a new equilibrium is established)
 WALTER NERNST
Relates the voltage of electrochemical cells to their chemical
thermodynamics Nernst equation is an equation that relates the
reduction potential of a half cell (or the total voltage, i.e. the
electromotive force, of the full cell) at any point in time to the standard
electrode potential, temperature, activity, and reaction quotient of the
underlying reactions and species used
 STEPHEN HAWKING
One of the most eminent scientist after Einstein. Stephen Hawking
predicts that black holes will radiate particles with a blackbody
spectrum which can cause black hole evaporation

Applications
Heat Engines
 One of the most important
things we can do with heat
is to use it to do work for us.
A heat engine does exactly
this.
 It makes use of the
properties of
thermodynamics to
transform heat into work.

Applications
 Heat pumps, air conditioners, and refrigerators utilize
heat transfer of energy from low to high temperatures,
which is the opposite of what heat engines do.
 The purpose of a heat pump is to transfer energy by
heat to a warm environment, such as a home in the
winter

END