What are the conditions for a process to be reversible?
Reversible processes is differentially removed from equilibrium with no (appreciable) internal temperature, pressure, and velocity changes. A reversible process can be reversed at any point by external conditions.
Which process can not return to the system and surroundings?
In science, a process that is not reversible is called irreversible. This concept arises frequently in thermodynamics. A system that undergoes an irreversible process may still be capable of returning to its initial state. However, the impossibility occurs in restoring the environment to its own initial conditions.
In which of the following process the system and surrounding do not come back to original state after the process is complete?
An example of a quasi-static process that is not reversible is a compression against a system with a piston subject to friction—although the system is always in thermal equilibrium, the friction ensures the generation of dissipative entropy, which directly goes against the definition of reversible.
Is an adiabatic process reversible?
It is an idealized thermodynamic process that is adiabatic and in which the work transfers of the system are frictionless; there is no transfer of heat or of matter and the process is reversible.
Does adiabatic mean constant temperature?
An adiabatic process is defined as a process in which no heat transfer takes place. This does not mean that the temperature is constant, but rather that no heat is transferred into or out from the system.
How do you know if a process is adiabatic?
An adiabatic process is one in which no heat is gained or lost by the system. The first law of thermodynamics with Q=0 shows that all the change in internal energy is in the form of work done. This puts a constraint on the heat engine process leading to the adiabatic condition shown below.
Which is constant in adiabatic process?
An adiabatic process is a thermodynamic process during which no energy is transferred as heat across the boundaries of the system. As there is no exchange of heat with surroundings, so total heat of the system remains constant.
What is CP and CV?
In thermodynamics, the heat capacity ratio or ratio of specific heat capacities (Cp:Cv) is also known as the adiabatic index. It is the ratio of two specific heat capacities, Cp and Cv is given by: The Heat Capacity at Constant Pressure (Cp)/ Heat capacity at Constant Volume(Cv)
Why entropy is constant in adiabatic process?
According to thermodynamics, a process is said to be adiabatic if no heat enters or leaves the system during any stage of the process. As no heat is allowed to transfer between the surrounding and system, the heat remains constant. Therefore, the change in the entropy for an adiabatic process equals to zero.
Is adiabatic process quasi static?
Summary. A quasi-static adiabatic expansion of an ideal gas produces a steeper pV curve than that of the corresponding isotherm. A realistic expansion can be adiabatic but rarely quasi-static.
Is reversible process quasi-static?
A process, carried out in a stepwise manner, becomes quasi-static when the number of intermediate steps tends to infinity. Usually, the net entropy production approaches zero under this limiting condition. Hence, such cases are termed reversible.
Why quasi-static process is important?
Equilibrium in a system in a quasi-static process is established many times more rapidly than change in the physical parameters of the system. Quasi-static processes play an important role in thermodynamics, since thermodynamic cycles including only quasi-static processes yield maximum work values.
Is free expansion quasi-static?
4 Answers. The free expansion is an irreversible process so that there are no equilibrium states joining the initial and the final one. For this reason the notation dU and similar ones is inappropriate: no infinitesimal changes exist here.
What do you mean by quasi static process?
In thermodynamics, a quasi-static process (also known as quasi-equilibrium, from the Latin quasi, meaning ‘as if’), is a thermodynamic process that happens slowly enough for the system to remain in internal equilibrium. Any reversible process is a quasi-static one.
What is true for free expansion process?
In free expansion there is no work done as there is no external external pressure. That’s certainly true, in fact free expansion is an irreversible process in which a gas expands into an insulated evacuated chamber, you can think of it like ann container with a piston and the gas is left to expand in vacuum.
Why is free expansion irreversible?
Since the system is isolated from the surroundings during the free expansion of the system, the surroundings does not partake in that process. Thus there is a positive total entropy change of the universe (system + surroundings) making the entire process irreversible.
What happens when gas is cooled?
If a gas is cooled, its particles will eventually stop moving about so fast and form a liquid. This is called condensation and occurs at the same temperature as boiling. Evaporation is dependent on individual particles gaining enough energy to escape the surface of the liquid and become gas particles.
When a gas is allowed to expand what will be its effect on its temperature?
As a gas (like air) expands, the value of V increases and this has the effect of increasing T (The temperature). As the energy needed to increase it’s temperature must be supplied from somewhere, the gas takes the energy from the surrounding system giving the effect of cooling.
Why does heat cause gas to expand?
The temperature of a gas is a measure of the speed of its molecules. When the bottle is heated, the air molecules inside start moving faster. These molecules now collide into the balloon with more energy resulting in increased pressure. The increased pressure causes the balloon to expand.
Does air expand more than water when heated?
Air at the temperature of freezing water, has its volume doubled when heated 491 degrees, and when heated 982 degrees, or twice as intensely, its volume is tripled, which is the effect of a low red heat.
Do gases expand to fill their container?
Gases are in rapid motion, and they undergo elastic collisions with each other and the walls of the container; that is, momentum and energy is transfered not lost during collisions. Gases expand spontaneously to fill any container (rapid motion).
Is it possible to increase the temperature of a gas without giving it heat?
Yes, during adiabatic compression the temperature of a gas increases while no heat is given to it. In compression work is done on the gas i.e. , work done is negative. Hence, internal energy of the gas increases due to which its temperature increases.
When an ideal gas expands there is no change in temperature?
In an ideal gas, there are no intermolecular forces of attraction. Hence, no energy is required to overcome these forces. Hence, internal energy of the system does not change i.e. there is no absorption or evolution of heat. In case of a real gas upon expansion , the temperature increases and the molecules move slowly.
When a gas undergoes adiabatic expansion it gets cold due to?
Solution : Due to fall in temperature. Step by step solution by experts to help you in doubt clearance & scoring excellent marks in exams.