F. Y. B. Sc. Semester I Paper - I

1. Thermodynamics
Manohar Jopale
Arts Commerce and Science College Trimbakeshwar district Nashik

2. Introduction
Thermo means heat and dynamics means motion or mechanical
work.
hence the thermodynamics is branch of science which deals with the
quantitative relationship between heat and other form of energy
There are first second and third law of thermodynamics but
nothing country to law has been reported so far zeroth law of
thermodynamics which help us understand the concept of
temperature was put forward letter

3. Objectives of thermodynamics
 I. To predict the feasibility of a process:
whether or not, cockroaches will be occur under given set of
condition can be predicted by applying the principle of
thermodynamics
ii. To estimate the yield of product:
It is possible to know what extent the reaction attend equilibrium
iii. To deduce some important relationship:
like Raoult’s law of lowering of vapor pressure, depression in freezing point,
elevation in boiling point, distribution law, phase rule from the study of
thermodynamics

4. Limitation of thermodynamics
Thermodynamics suffer from certain limitation these are:
1. Deals with the properties like temperature pressure except of the matter in bulk
of macroscopic quantities and not in microscopic quantities. it deals with
large group of atom molecules and ions rather than individual atom or
molecule or iron
2. It help to predict the feasibility of a process but gives no idea about time taken
for process to complete
3. It treatment it is limited to initial and final state of system and is simul silent
about the path by which change is brought about

5. Zeroth law of thermodynamics
Statement:
When two systems have equality of temperature with third system there is turn have equiality of
temperature with each other for example,
System A have thermal equilibrium to B and B have thermal equilibrium to C then the A is also
having thermal equilibrium C according to Zeroth law of thermodynamics.
BA C

6. First law of thermodynamics
 Statements: first law of thermodynamics is stated in number of ways
1. Energy can neither be created nor be destroyed all through it may be converted from one form to the another form.
2. Total energy of an isolated system remain constant although it may undergo transformation from one form to the
other
3. Whenever a certain quantity of some form of energy disappear and exactly equivalent amount of some other form
of energy must be produced
4. Impossible to construct perpetual motion machine damn it means machine which would produce work continuously
without consuming energy
Einstein in 1905 show that energy could be created by destruction of masses the energy produced is capital e by
the destruction of masses m is given by equation ,
E = mc2. (Einstein equation)
Modified statement for first law of thermodynamics is the total masses and energy of an isolated system remain constant

7. Mathematical equation for first law of
thermodynamics
 If heat is supplied to a system it may be used up personally partly to increase the internal energy
of system and partly to do some mechanical work if delta u is the increase in internal energy of
system and w is work done by system then we have equation
∆ U OR E = q + w (1)
if the work done of expansion,
W = -P∆V
Or q = ∆ U + P∆V (2)
IF CHANGES ARE VERY SMALL, IT MAY BE WRITTEN AS,
q = dU + P∆V (3)
Equation 1 & 3 is called mathematical equation for first law of
thermodynamics.

8. Second law of thermodynamics
Statement:
1. All spontaneous processes are thermodynamically irreversible for example flow of heat from hot body
to cold in diffusion of gas from high pressure to low pressure flow of water down a hill accept etc.
2. Spontaneous process means a process which can takes place without the help of any external agency
and all natural processes are called as spontaneous processes
3. Complete conversion of heat into work is impossible without leaving some efforts elsewhere
4. It’s impossible to construct a machine functioning in cycle which are convert heat completely into
equivalent amount of work without producing changes elsewhere
5. Without the use of an external agency heat cannot be itself pass from cold to hot body
6. Per new thermodynamic function entropy second law is also stated as in entropy of universe is always
toward the Maxima

9. Thank you