Question

Argon in the amount of 1.5 kg fills a 0.04-m3 piston cylinder device at 550 kPa. The piston is now moved by changing the weights until the volume is twice its original size. During this process, argon's temperature is maintained constant. Determine the final pressure in the device. Assumptions: At specified conditions, argon behaves as an ideal gas. Properties: The gas constant of argon is R 0.2081 kJ/kgK

Answer 1

275 kPa

Step-by-step explanation:

mass of the gas=m=1.5 kg

initial volume if the gas=V₁=0.04 m³

initial pressure of the gas= P₁=550 kPa

as the condition is given final volume is double the initial volume

V₂=final volume

V₂=2 V₁

As the temperature is constant

T₁=T₂=T

`(P1V1)/(T1)`=
`(P2 V2)/(T2)`

putting the values in the equation.

`(P1V1)/(T1)`=
`(P2 *2V1)/(T2)`

P₂=
`(P1)/(2)`

P₂=
`(550)/(2)`

P₂=275 kPa

So the final pressure of the gas is 275 kPa.