Is isothermal expansion of ideal gas reversible?
Hence, a reversible isothermal expansion is an infinitely-slow increase in volume at constant temperature. All the reversible isothermal PV work wrev done by an ideal gas to expand was possible by reversibly absorbing heat qrev into the ideal gas.
What is reversible expansion of an ideal gas?
The only way this is possible is if the pressure of the expanding gas is the same as the external pressure resisting the expansion at all points along the expansion. With no net force pushing the change in one direction or the other, the change is said to be reversible or to occur reversibly.
What is isothermal expansion of an ideal gas?
Hint: The isothermal expansion means a gas is expanding from initial volume to final volume at constant temperature. The internal energy and enthalpy depend upon the temperature only in case of ideal gas. So, during the isothermal expansion of an ideal gas, the temperature remains constant and volume increases.
Why is isothermal expansion reversible?
You clearly cannot undo expansion into a system that had 0 pressure if you only have a piston pushing on one side. Therefore, it is irreversible, as stated first thing in the article. A reversible isothermal expansion is an infinitisimally slow increase in the volume of the substance at constant temperature.
What is irreversible isothermal expansion?
A. In case of isothermal irreversible expansion , the gas is allowed to expand slowly , its temperature tends to fall but some of the heat from the surrounding is conducted to the gas , keeping the temperature constant . …
How do you calculate expansion work?
Pressure-volume work
- Work is the energy required to move something against a force.
- The energy of a system can change due to work and other forms of energy transfer such as heat.
- Gases do expansion or compression work following the equation: work = − P Δ V \text {work} = -\text P\Delta \text V work=−PΔV.
What happens during isothermal expansion of ideal gas?
Isothermal Expansion Temperature is held constant, therefore the change in energy is zero (U=0). So, the heat absorbed by the gas equals the work done by the ideal gas on its surroundings. Enthalpy change is also equal to zero because the change in energy zero and the pressure and volume is constant.
How is isothermal expansion calculated?
An ideal gas obeys the equation of state PV = RT (V = molar volume), so that, if a fixed mass of gas kept at constant temperature is compressed or allowed to expand, its pressure and volume will vary according to PV = constant. That is, Boyle’s Law.
Why free expansion is not reversible?
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.
Is free expansion isothermal process?
If there is also no work done, i.e. a free expansion, there is no change in internal energy. For an ideal gas, this means that the process is also isothermal.
How to calculate the energy of an isothermal reversible expansion?
For an isothermal reversible expansion of an ideal gas, we have by definition that Δ T = 0. Since the energy of an ideal gas depends only on the temperature, a constant temperature implies constant energy, so that Δ E = 0 = q r e v + w r e v. Using the equation we find for w r e v in the previous section, we have
How to calculate the reversible expansion of an ideal gas?
For an isothermal reversible expansion of an ideal gas, we have by definition that \\Delta T=0. Since the energy of an ideal gas depends only on the temperature, a constant temperature implies constant energy, so that \\Delta E=0=q^ {rev}+w^ {rev}. Using the equation we find for w^ {rev} in the previous section, we have
When does free expansion of a gas occur?
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).
What is the internal energy of an ideal gas?
The entire internal energy in an ideal gas is in the form of kinetic energy of the particles and any change in the internal energy results in a change of temperature. Now that we have a basic understanding of the concept of an ideal gas let us see what the meaning of an isothermal expansion is and what is isothermal process.