MEDIUM
Earn 100

Why work done in a free expansion of ideal gas is zero?

Important Questions on Thermodynamics

EASY
Calculate the work done during compression of 2 mol of an ideal gas from a volume of 1m3 to 10 dm3 at 300 K against a pressure of 100 kPa.
EASY

Under the isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is

(Given that 1 L bar=100 J)

MEDIUM
The correct option for free expansion of an ideal gas under adiabatic condition is
EASY
A gas can expand from 100 mL to 250 mL under a constant pressure of 2 atm. The work done by gas is
EASY
An ideal gas undergoes isothermal expansion at constant pressure. During the process:
HARD
During the free expansion of an ideal gas in an isolated chamber,
 
EASY
Five moles of an ideal gas at 1 bar and 298 K is expanded into vacuum to double the volume. The work done is :
EASY
Three mole of an ideal gas expand isothermally and reversibly from 10 m3 to 20 m3 at 300 K, calculate the work done? R=8.314 J K-1 mol-1
MEDIUM
A gas is allowed to expand in a well-insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy ΔU of the gas in joules will be
EASY
If 100 mole of H2O2 decompose at 1 bar and 300 K, the work is done (kJ) by one mole of O2(g) as it expands against 1 bar pressure is:

2H2O2l2H2Ol+O2(g)

R=8.3 J K-1 mol-1
MEDIUM
An ideal gas initially at temperature, pressure and volume, 27°C,1.00 bar and 10 L respectively is heated at constant volume until pressure is 10.0 bar, it then undergoes a reversible isothermal expansion until pressure is 1.00bar, what is the total work W, during this process?
HARD
A cylinder containing an ideal gas ( 0.1mol of 1.0dm3 ) is in thermal equilibrium with a large volume of 0.5 molal aqueous solution of ethylene glycol at its freezing point. If the stoppers S1 and S2 (as shown in the figure) are suddenly withdrawn, the volume of the gas in litres after equilibrium is achieved will be _____________.
(Given, Kfwater=2.0Kkgmol-1,R=0.08dm3atmK-1mol-1

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EASY
Calculation the maximum work done in expanding 16 gof oxygen at 300 K and occupying a volume of 5 dm3 isothermally until volume becomes 25 dm3.
EASY
An ideal gas expands adiabatically against vacuum. Which of the following is correct for the given process?
MEDIUM
Five moles of an ideal gas at 293 K is expanded isothermally from an initial pressure of 2.1 MPa to 1.3 MPa against at constant external pressure 4.3 MPa. The heat transferred in this process is ___ kJmol-1. (Rounded-off to the nearest integer)

[ Use R=8.314 J mol-1 K-1]

MEDIUM
For water at 100°C and 1 bar,
Δvap H-Δvap U=¯×102 J mol-1
(Round off to the Nearest Integer)
[Use : R=8.31 J mol-1 K-1
[Assume volume of H2O(l) is much smaller than volume of H2O(g). Assume H2O(g) treated as an ideal gas]
HARD

At 25°C,50 g of iron reacts with HCl to form FeCl2. The evolved hydrogen gas expands against a constant pressure of 1 bar. The work done by the gas during this expansion is -_______ J.

(Round off to the Nearest Integer)

[Given : R=8.314 J mol-1 K-1. Assume, hydrogen is an ideal gas]

[Atomic mass off Fe is 55.85 u]

MEDIUM

The magnitude of work done by a gas that undergoes a reversible expansion along the path ABC shown in the figure is _________.
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HARD
An ideal gas undergoes isothermal compression from 5 m3 to 1 m3 against a constant external pressure of 4 N m-2. The heat released in this process is 24 J mol-1K-1 and is used to increase the pressure of 1 mole of Al. The temperature of Al increases by:
MEDIUM
4.0 L of an ideal gas is allowed to expand isothermally into vacuum until the total volume is 20 L. The amount of heat absorbed in this expansion is ____L atm.