Choose the correct option for free expansion of an ideal gas under adiabatic condition from the following: [2024]
(D) For adiabatic process .
By first law of thermodynamics:
For an ideal gas internal energy is function of temperature, so if is also 0.
If 5 moles of an ideal gas expands from 10 L to a volume of 100 L at 300 K under isothermal and reversible condition then work, w, is J. The value of is _________ .
(Given R = 8.314 J ) [2024]
(28721)
For isothermal reversible process, work W is given by:
The heat of combustion of solid benzoic acid at constant volume is –321.30 kJ at 27°C. The heat of combustion at constant pressure is (–321.30 – R) kJ, the value of is _________ . [2024]
(150)
for water is + 40.79 kJ at 1 bar and 100°C. Change in internal energy for this vapourisation under same condition is ________ kJ . (Integer answer)
(Given R = 8.3 ) [2024]
(38)
If three moles of an ideal gas at 300 K expand isothermally from 30 to 45 against a constant opposing pressure of 80 kPa, then the amount of heat transferred is _____ J. [2024]
(1200)
[IMAGE 8]
Work (W) against constant pressure is calculated as:
By first law of thermodynamics:
For isothermal process of an ideal gas,
So,
Hence 1200 J of heat is absorbed in the process.
[IMAGE 9]
An ideal gas undergoes a cyclic transformation starting from the point A and coming back to the same point by tracing the path as shown in the diagram above. The total work done in the process is _____ J. [2024]
(200)
Magnitude of work done in a cyclic process = area enclosed by P-V or V-P graph.
[IMAGE 10]
Consider the figure provided.
1 mol of an ideal gas is kept in a cylinder, fitted with a piston, at the position A, at 18°C. If the piston is moved to position B, keeping the temperature unchanged, then ‘x’ L atm work is done in this reversible process.
x = _____ L atm. (nearest integer)
[Given: Absolute temperature = °C + 273.15,
R = 0.08206 L atm ] [2024]
(55)
Work done by gas in isothermal reversible expansion is:
Work done by system = +55 atmL