What is partial
pressure?
The partial pressure of each constituent is that pressure
which the gas would exert if it occupied alone that volume occupied by the
mixtures at the same temperature.
What is compressibility factor?
The gas equation for an ideal gas is given by (PV/RT) = 1,
for real gas (PV/RT) is not equal to 1
(PV/RT) = Z for real gas is called the compressibility factor.
for real gas (PV/RT) is not equal to 1
(PV/RT) = Z for real gas is called the compressibility factor.
How does the Vander
Waal’s equation differ from the ideal gas equation of state?
The ideal gas equation pV=mRT has two important assumptions,
1. There is little or no attraction between the molecules of
the gas.
2. That the volume occupied by the molecules themselves is
negligibly small compared to the volume of the gas. This equation holds good
for low pressure and high temperature ranges as the intermolecular attraction and the volume of the molecules
are not of much significance.
As the pressure increases, the inter molecular forces of
attraction and repulsion increases and the volume of the molecules are not negligible. The real gas
deviates considerably from the ideal gas equation [p+(a/V2)](V-b) = RT
What is
humidification and dehumidification?
The addition of water vapour into air is humidification and
the removal of water vapour from air is dehumidification.
What are the
important psychrometric processes?
1. Sensible
heating and sensible cooling,
2. Cooling
and dehumidification,
3. Heating
and humidification,
4. Mixing of
air streams,
5. Chemical
dehumidification,
6. Adiabatic
evaporative cooling.
What is meant by
adiabatic mixing?
The process of mixing two or more stream of air without any
heat transfer to the surrounding is known as adiabatic mixing. It is happened
in air conditioning system.
What are the
assumptions made in Vanderwaal’s equation of state?
1. There is no inter molecular forces between particles.
2. The volume of molecules is negligible in comparison with
the gas.
What is coefficient
of volume expansion?
The coefficient of volume expansion is defined as the change
in volume with the change in temperature per unit volume.
What are
thermodynamic properties?
Thermodynamic properties are pressure (p), temperature (T),
volume (V), internal energy (U), enthalpy(H), entropy (S), Helmholtz function and Gibbs
function
Define throttling process.
When a fluid expands through a minute orifice or slightly
opened valve, the process is called as throttling process. During this process, pressure and
velocity are reduced.