this is a presentation on first law of thermodynamics

1. Bangabandhu Sheikh Mujibur Rahman Science
and Technology University
A presentation on first law of
thermodynamics
Presented by
Md. Shimul Bhuia
St. ID: 16PHR003
Department of Pharmacy

3. Thermodynamics
• Thermodynamics is a branch of physics
concerned with heat and temperature and
their relation to energy and work .In
particular, it describes how thermal energy is
converted to and from other forms of energy
and how it affects matter.

4. The first law of thermodynamics
• The first law of thermodynamics states that
the amount of heat given to a system is equal
to the sum increase in the internal energy of
the system and the external work done.

5. Thermodynamics systems
• A thermodynamic
system is the
material and
radiative content of
a macroscopic
volume in space,
that can be
adequately
described by
thermodynamic
state variables such
as temperature,
entropy, internal
energy and pressure

6. Statement of the first law of
thermodynamics
• Conservation of energy
• Energy can neither be created nor destroyed
but it can change forms
• Total amount of energy in a closed system
remains constant

7. Description with formula
• Heat/work
formula:
ΔU=Q-W
• dU= Δ Q-PdV
[W=PdV]

8. Significance
• The total amount of energy in the world is
constant.
• It is impossible to get more energy oyt of a
system than is put into it.
• You can’t get energy from nothing.

9. Application
• Can be used to find the latent heat of
vaporization
• It is used to calculate the quantity to raise the
temperature of an ideal gas

10. Limitation of first law
Limitation:- First law
does not help to
predict whether the
certain process is
possible or not.
Reason:- It does not
specify that heat
cannot flow from low
temperature body to a
high temperature body
Limitation:-The first law
does not give
information about
direction.
Reason :For example it
puts no restriction on
the direction of the
flow of heat, whether
heat can flow from a
cold body to a hot body
or vice versa.

11. Conclusion
• The 1st law of thermodynamics simply says
that the amount energy in a closed system
remains constant.
• Regardless of how it is changed or is moved
around.
• To add energy to a system it needs to come
from some place else