Question

An ideal gas is expanded irreversible against 10 bar pressure from 20 litre to 30 litre. Calculate 'q' if the process is isenthalpic.
(a) 0
(b) +100J
(c) -100J
(d) +10KJ

Answer 1

The ideal gas law also known as the ideal gas equation. It is the equation of state of a hypothetical ideal gas. It is a good approximation of behavior of many gases under many conditions although it has many limitations.

Complete step by step solution:
We have been provided by the ideal gas equation, $PV=nRT$
Where P = pressure of the gas
V = volume of the gas
N = amount of substances
R = gas constant
T = temperature of the gas
Given in the question:
Pressure = 10 bar
Change in volume i.e. initial volume = 20 l
And final volume = 30 l
And it is mentioned that the pressure is isenthalpic i.e.
${{W}_{irr}}=-{{P}_{opp}}({{V}_{2}}-{{V}_{1}})=-10(30-20)$
$\implies$ $(-98.69atm)(10litre)=-98.69-1$
$\implies$ $-9999.76$
$\therefore$ $-10KJ$
Since the change in enthalpy is 0 and the work done will be equal to the –q.

Hence the correct answer is option (D)

Additional information:
An ideal gas is gas that conforms the physical behavior to a particular idealized relation between the pressure, volume and the temperature known as the ideal gas. There are different values of the universal gas constant which is selected according to the unit of other units given in the question.

Note: The ideal gas relates the four independent physical properties of a gas at any time. The ideal gas law can be used in the stoichiometry problems in which the chemical reactions involve gases. The standard temperature and pressure STP are a useful set of the benchmark conditions to compare the other properties of gases.