What is free expansion class 11?

In free expansion (a gas) expands in such a way that no heat enters or leaves the system (adiabatic process) and also no work is done by or on the system, then the expansion is called the free expansion. Uf​−Ui​=Q−W, Now Q=0,W=0. ∴Uf​=Ui​.

What happens in free expansion of gas?

The free expansion of a gas is a process in which a gas is allowed to expand into the vacuum. Thus, the change in the internal energy of the ideal gas in free expansion is zero. As the change in the internal energy of an ideal gas in the free expansion is zero. Thus, option (A) remains constant is correct.

What is cyclical and free expansion process?

In a cyclic process the system returns to its initial state and so the internal energy is not changed. A free expansion is an adiabatic change that does no work.

Is free expansion possible?

The free expansion of a gas is an irreversible process; in principle, the temperature of a gas undergoing a free expansion is not a meaningful quantity. When we talk about an isothermal free expansion of a gas, we mean that the final temperature is the same as the initial temperature.

What is free expansion Shaalaa?

Free expansions are adiabatic expansions thus there is no exchange of heat between a system and its environment. 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.

What is free expansion and what is the work done during the expansion of an ideal gas both in reversible and irreversible process?

What is the work done in the free expansion of an ideal gas in reversible and irreversible processes? In both cases work done is zero because during free expansion of an ideal gas external pressure becomes zero.

What is free expansion in physics?

The Joule expansion (also called free expansion) is an irreversible process in thermodynamics in which a volume of gas is kept in one side of a thermally isolated container (via a small partition), with the other side of the container being evacuated.

What are the conditions of free expansion?

Free expansion of a gas occurs when it is subjected to expansion in a vacuum (pex=0). During free expansion of an ideal gas, the work done is 0 be it a reversible or irreversible process. Where ∆U represents the change in internal energy, q is the heat given by the system and w is the work done on the system.

What is difference between free expansion and throttling process?

Throttling is the irreversible thermodynamic process in which the fluid is forced through a nozzle causing a pressure drop. Whereas, in free expansion the gas or fluid just expands into the evacuated chamber. This process is also irreversible and here also the work done and heat excnage are zero.

What is meant by free expansion in vacuum?

In a free expansion, gas is allowed to expand into a vacuum. This happens quickly, so there is no heat transferred. No work is done, because the gas does not displace anything.

What is the relation between ∆ H and ∆ U?

The change in the internal energy of the system in the chemical reaction is \[\Delta U\]. The change in the enthalpy of the system in the chemical reaction is \[\Delta H\]. According to the above discussion, we conclude that the relation between \[H\] and \[U\] is\[\Delta H = \Delta U + P\Delta V\].

What is meant by free expansion?

Free Expansion. In a free expansion, gas is allowed to expand into a vacuum. This happens quickly, so there is no heat transferred. No work is done, because the gas does not displace anything.

What is the work done during free expansion of gas?

Free expansion of a gas occurs when it is subjected to expansion in a vacuum (p ex=0). During free expansion of an ideal gas, the work done is 0 be it a reversible or irreversible process. It is known that the change in internal energy of a system is given as: ∆U = q + w—(1)

What is the difference between isothermal and free expansion?

Isothermal expansion. An isothermal process is a change in the system such that the temperature remains constant. In other words, in isothermal process ∆T = 0. Free expansion of a gas occurs when it is subjected to expansion in a vacuum (p ex =0). During free expansion of an ideal gas, the work done is 0 be it a reversible or irreversible process.

Why is the work done in a free expansion Zero?

In the case of a free expansion the external pressure is zero hence the work done is zero. another way of looking at it is, work is the transfer of energy between the system and surroundings when there are imbalanced forces between them.