What is Carnot
principle?
No irreversible engine operating between two reservoirs at
constant temperatures can have a greater efficiency than a reversible engine
operating between the same temperatures.
Furthermore, all reversible engines operating between the
same temperatures have the same efficiency.
What are the
limitations of carnot cycle?
1. No friction is considered for moving parts of the engine.
2. There should not be any heat loss.
What is Specific heat
capacity at constant pressure?
It is defined as the amount of heat energy required to raise
or lower the temperature of unit mass of the substance through one degree when
the pressure kept constant. It is
denoted by Cp.
What is Specific heat
capacity at constant volume?
It is defined as the amount of heat energy required to raise
or lower the temperature of unit mass of the substance through one degree when
volume kept constant.
What is meant by
surroundings?
Any other matter outside the system boundary is called as
surroundings.
What is boundary?
System and surroundings are separated by an imaginary line
is called boundary.
What is Entropy?
Entropy is a measure of the disorder of a system. Its value
depends upon the state of the system; hence it is a state function. On
increasing the temperature, the molecular motion increases. Hence, entropy will
increase with increase of temperature.
Important
characteristics of entropy are given below:
1. If the heat is supplied to the system then the entropy
will increase.
2. If the heat is rejected to the system then the entropy
will decrease.
4. The entropy increases if temperature of heat is lowered
without work being done as in
throttling
process.
5. If the entropy is maximum, then there is a minimum
availability for conversion in to work.
6. If the entropy is minimum then there is a maximum
availability for conversion into work.
7. Entropy will decrease because solids have smaller
randomness molecules.
8. Entropy will increase because a substance in vapour state
is formed.
9. Entropy is decreased because the total numbers of
molecules are decreased.
What is Enthalpy?
Enthalpy is the sum of internal energy and the product of
pressure and volume of the system.
H = E + PV
Internal energy is the energy stored in a substance.
Define thermodynamic
equilibrium.
If a system is in Mechanical, Thermal and Chemical
Equilibrium then the system is in thermodynamically equilibrium. Or
If the system is
isolated from its surrounding there will be no change in the macroscopic
property, then the system is said to exist in a state of thermodynamic
equilibrium.
What is Property?
A property is an
observable. It results from a physical
or chemical measurement. A system is characterized
by a set of properties. Typical examples
are mass, volume, temperature, pressure, moisture content, chemical
composition, energy, etc. Properties may be classified as intensive or
extensive.
Intensive property:
A property that
characterizes the system as a whole, and is not given as the sum of the
property for portions of the system.
Pressure, temperature, density, water vapor mixing ratio,
and specific heat are examples of intensive properties.
Extensive property:
A property which is dependent
on the extent or physical size of the system, and which is given by the sum of
the extensive properties of portions of the system.
Examples are mass,
volume and energy.