2. What is Thermodynamics?
OThermodynamics: A set of of mathematical
models and concepts that allow us to describe
the way changes in the system state
(temperature, pressure, and composition)
affect equilibrium.
O Can be used to predict how rock-forming systems
will respond to changes in state
O Invert observed chemical compositions of minerals
and melts to infer the pressure and temperature
conditions or origin
3. Types of Thermodynamic
System:
O Thermodynamic systems can be broadly
classified into three types. They are:
O Open system
O Closed system
O Isolated system
4. 1. Open System:
O An open system is
a thermodynamic
system which
allows both mass
and energy to flow
in and out of it,
across its boundary.
The image below
illustrates open
system.
5. Example of Open system:
O Water heated in an
open container –
Here, heat is the
energy transferred,
water is the mass
transferred and
container is the
thermodynamic
system. Both heat
and water can pass in
and out of the
container.
6. 2. Closed System:
O A closed system
allows only energy
(heat and work) to
pass in and out of it. It
does not allow mass
transfer across its
boundary. The
following image
shows a closed
system:
7. Example of Closed system:
O Water heated in a
closed vessel –
Here only heat
energy can pass in
and out of the
vessel.
8. 3. Isolated System:
O An isolated system
does not interact with its
surroundings. It does
not allow both mass and
energy transfer across
its boundary. It is more
restrictive.
O In reality, complete
isolated systems do not
exist. However, some
systems behave like an
isolated system for a
finite period of time.
9. Example of Isolated system:
O A perfectly
insulated, rigid and
closed vessel is
an example of an
isolated system as
neither mass nor
energy can enter or
leave the system.