h = u+ Pv
For an ideal gas u = u(T) only and PV = mRT and hence h = h(T) only.
The specific heat at constant volume is defined as the amount of energy transferred as
heat at constant volume, per unit mass of a system to raise its temperature by one degree
We introduce boundaries in our study called the system and surroundings.
The boundaries are set up in a way most conducive to understanding the energetics of what we're
Defining the system and surroundings is arbitrary, but it becomes important
Control volume is a volume in space of special interest for particular analysis.
The surface of the control volume is referred as a control surface and is a closed surface.
The surface is defined with relative to a coordinate system that may be fixed, mov
The state of the system is described by its properties.
Once a sufficient number of properties are specified, the rest of the properties assume
some values automatically.
The number of properties required to fix a state of a system is given by the state
A process is said to be reversible if both the system and its surroundings can be restored to their
respective initial states by reversing the direction of the process.
reversible: if the process happens slow enough to be reversed.
irreversible: if the
Step 1. Identify the system and draw a sketch of it. The system that is about to be analyzed
should be identified on the sketch by drawing its boundaries using the dashed lines.
Step 2. List the given information on the sketch. Heat and work interactions
The molecule as a whole can move in x, y and z directions with respective
components of velocities and hence possesses kinetic energy.
There can be rotation of molecule about its center of mass and than the kinetic
energy associated with
Pure Substance: A pure substance is one that has a homogeneous and invariable chemical
composition. It may exist in more than one phase but chemical composition is the same in all
Some times the mixture of gases, such as air is considered a pure s
The locus of all the saturated states gives the saturated liquid curve AC and the locus of all the
saturated vapor states gives the saturated vapor states gives the saturated vapor states gives the
saturated vapor curve BC.
The first law of thermodynamics is the thermodynamic expression of the conservation of
This law most simply stated by saying that energy can not be created or destroyed or that the
energy of the universe is constant.
This law can be stated for a s
The term saturation temperature designates the temperature at which vaporization takes
For water at 99.6 C the saturation pressure is 0.1 M Pa, and for water at 0.1 Mpa, the
saturation temperature is 99.6 C.
If a substance exists as liquid at the s