Answer:
a. 9.58kgs b. 340.32KJ
Explanation:
Volume of tank= 2m³
Initial Pressure Pi= 100KPa
Initial Temperature Ti= 22 C= 295K
Line Pressure P₁= 600 KPa
Line Temperature T= 22 C= 295K
Final Pressure P2= 600 KPa
Final Temperature T2= 77 C= 350K
Use Ideal Gas Equation
PV= mRT
P₁V₁= m₁RT₁
m₁= (100 x 2)/(0.287 x 295) = 2.3622kg
P₂V₂= m₂RT₂
m₂= (600 x 2)/(0.287 x 350) = 11.946 kg
Since valve is closed and no mass leave
m₁ + mi = m₂ + me
as per above condition me= 0
mi= m₂ - m₁ = 11.946 - 2.3622 = 9.5838kg
Applying energy equation
m₁u₁ + mihi + Q = m₂u₂ + mehe + W
me and W=0
m₁u₁ + mihi + Q = m₂u₂
m₁CvT₁ + miCpTi + Q = m₂CvT₂
Q = m₂CvT₂- m₁CvT₁ - miCpTi
Q = (11.946 x 0.717 350) - (2.3622 x 0.717 x 295) - (9.5868 x 1.004 x 295)
Q = -340.321 KJ (Negative sign doesn't matter as energy is not a vector quantity)
