A cylinder fitted with a piston has an initial volume of 0.1m 3 and contains Nit

Question

A cylinder fitted with a piston has an initial volume of 0.1m3 and contains Nitrogen at a pressure of 150kPa and a temperature of 25oC. The piston is moved, compressing the Nitrogen until the pressure is 1MPa and the temperature is 150oC. During the compression process heat is transferred from the Nitrogen to the surroundings and the work done on the Nitrogen is 20kJ.       ///////

i) What is the mass of Nitrogen in the cylinder  kg ?      (      ?          )     ///////

ii) The change in internal energy of the Nitrogen  kJ ? (     ?       )    //////

iii) Hence the boundary heat transfer  kJ ? (       ?       ) //////

You may assume that Nitrogen behaves as an ideal gas with a molecular weight of 28 kg/kmol :

Ideal Constant Volume Specific Heat Capacity, Cv0=745 J/kg K

Universal Gas constant, R=8314 J/kmol K

SHOW WORK PLEASE

Explanation / Answer

R=8.314/28=0.2964

a)PV=mRT

m=150*10^3*0.1/0.2969*10^3*298=0.1698 kg

b)change in internal energy=mcv(t2-t1)

=0.1698*745*125=15.812 kj

c)Q=w+delU=20+15.812=35.812 KJ

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.