Air expands in a horizontal cylinder $($closed by a movable piston$)$ from an initial pressure

and volume of p$1=5$ bar and V$1=100$ dm$3$

to a terminal pressure of p$1=2$ bar,

The expansion is so slow, that the process can be modelled as isothermal $($t$1=$ t$2=$ ta$).$

The ambient pressure and temperature is given to pa $=1$ atm and ta $=25$C respectively.

Due to the sealing gasket, the movement of the piston in the cylinder involves friction. The

enclosed air can be modelled as an ideal gas with a specific gas constant of Rs $=287\mathrm{.}09$ J

kgK $.$

a$)$ Determine the terminal volume and the mass of air enclosed in the cylinder.

b$)$ What amount of heat QV$,12$ has to be added to the gas to keep the process isothermal?

c$)$ Calculate the amount of work Wg$,12$ converted to heat due to friction of the sealing

gasket.

d$)$ Quantify the produced entropy for the total process.

Answer rating: 100% (QA)

This question involves thermodynamics particularly the case of an isothermal expansion of an ideal gas inside a cylinder The initial conditions final ... View the full answer