Question

5 kg of air (R 287 J/kgK) fills a weighted piston-cylinder device at 50 kPa and 0°C. The device is heated until the temperature is 100°C. Determine the initial volume, the final volume, and the work done during this process.

Answer 1

Answer:

143.5 KJ

Explanation:

We have given mass=5 kg

vlaue of R Which is a constant =287 J/kgk

P=50 KPa

T₁=0°C=273K

T₂=100°C=100+273=373K

we know the standard equation of ideal gas=PV=mRT

Here we have to calculate volume using above equation

v₁=\frac{287\times 5\times 273}{50\times 1000}

v₁=7.833$m^{3}$

for constant pressure

$\frac{V1}{T1}$=$\frac{V2}{T2}$

Using this formula

v₂=$\frac{373}{273}$×7.8351

=10.705$m^{3}$

work done = Pdv

=50×$10^{3}$×(10.7051-7.8351)

=143.5 KJ