The document summarizes the four laws of thermodynamics: 1) The zeroth law establishes that thermal equilibrium is transitive. 2) The first law states that energy is conserved and relates heat, work, and changes in internal energy. 3) The second law says entropy always increases in spontaneous processes and Gibbs free energy always decreases. 4) The third law establishes that entropy reaches a minimum, zero, at absolute zero temperature.

1. Laws of
Thermodynamics
By: Golani Nirav

2. Law’s of Thermodynamics
Zeroth Law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
Third law of thermodynamics

3. Zeroth Law of Thermodynamics.
 “If object A is in thermal equilibrium with object B and B
is in thermal equilibrium with object C then A & C are in
thermal equilibrium with each other”
 if two closed system with different temperatures are come into
contact then heat is transferred from high temp. to law temp.
 it is the basis for temperature measurement of a body or object.
 This law is also used for designing the thermometer.

5. First law of thermodynamics
 “Energy can not be created nor can be destroyed there is only the
transformation of one form to another”
 In other word “the energy of whole universe is remain constant”
 It gives relation bw heat supplied & work done
∆Q = ∆U + ∆W
∆U =chang in I.E
∆Q =Heat given to system
∆W =work done by system
Δ Q = Δ U + Δ W

6. Second law of thermodynamics
 “In any spontaneous reaction the entropy of system is
always increase & gibb’s free energy is always decrease”
 Entropy is a randomness of dissorder
 2nd Law of Therm. says that nature always goes from order
to disorder
 The ice crystal molecules are much more ordered than the
free moving liquid water molecules.

7. Spontaneous reactions

8. Third law of thermodynamics
 “The entropy of any crystline material at absolute zero
temperature will be zero”
 The absolute zero temperature is the reference point for
determination entropy.
 Importance of this law
1. It helps in calculating the thermodynamic properties.
2. It explains the behavior of solids at very low temperature.