Advertisements
Advertisements
Question
Write a note on free expansion.
Advertisements
Solution
- Free expansions are adiabatic expansions thus there is no exchange of heat between a system and its environment.
- Also, there is no work done on the system or by the system. Q = W = 0, and according to the first law of thermodynamics, ΔU = 0.
- For example, when a balloon is ruptured suddenly, or a tire is suddenly punctured, the air inside rushes out rapidly but there is no displacement of a piston or any other surface.
- A free expansion is different than other thermodynamic processes because it is an uncontrolled change. It is an instantaneous change and the system is not in thermodynamic equilibrium.
- A free expansion cannot be plotted on a p-V diagram. Only it's initial and the final state can be plotted.
APPEARS IN
RELATED QUESTIONS
Explain why The climate of a harbour town is more temperate than that of a town in a desert at the same latitude.
A thermodynamic system is taken from an original state to an intermediate state by the linear process shown in Figure
Its volume is then reduced to the original value from E to F by an isobaric process. Calculate the total work done by the gas from D to E to F
Give an example of some familiar process in which heat is added to an object, without changing its temperature.
An ideal gas is taken through an isothermal process. If it does 2000 J of work on its environment, how much heat is added to it?
Draw a p-V diagram showing positive work with varying pressure.
State the assumptions made for thermodynamic processes.
An ideal gas of volume 2 L is adiabatically compressed to (1/10)th of its initial volume. Its initial pressure is 1.01 x 105 Pa, calculate the final pressure. (Given ЁЭЫ╛ = 1.4)
Explain work done during a thermodynamic process.
Explain thermodynamics of the adiabatic process.
Give an equation state for an isochoric process.
Draw the PV diagram for the adiabatic process.
Draw the PV diagram for the isobaric process.
What is meant by a reversible and irreversible processes?
Explain in detail the isothermal process.
Derive the work done in an isothermal process.
Explain in detail an adiabatic process.
Explain the isobaric process and derive the work done in this process.
Explain in detail the isochoric process.
In an adiabatic expansion of the air, the volume is increased by 4%, what is the percentage change in pressure? (For air γ = 1.4)
In a petrol engine, (internal combustion engine) air at atmospheric pressure and temperature of 20°C is compressed in the cylinder by the piston to `1/8` of its original volume. Calculate the temperature of the compressed air. (For air γ = 1.4)
A thermodynamic system undergoes cyclic process ABCDA as shown in the figure. The work done by the system is ______
A monoatomic gas of pressure p having volume V expands isothermally to a volume 2V and then adiabatically to a volume 16V. The final pressure of the gas is ____________.
`("ratio of specific heats" = 5/3)`
In which of the following processes, beat is neither absorbed nor released by a system?
We consider a thermodynamic system. If `Delta"U"` represents the increase in its internal energy and W the work done by the system, which of the following statements is true?
The work done on the system in changing the state of a gas adiabatically from equilibrium state A to equilibrium state B is 22.4 J. If the gas is taken from state A to B through another process in which the net heat absorbed by the system is 15.5 cal, then the net work done by the system in the latter case is ______.
( l cal = 4.2 J)
