Calculate q, w, delta U, delta T and delta S Consider a system consisting of 1.5

Question

Calculate q, w, delta U, delta T and delta S Consider a system consisting of 1.5 mol carbon dioxide gas, initially at 15 degreeC and 9.0 atm and confined to a cylinder of cross-section 100.0 cm^2. The sample is allowed to expand adiabatically against an external pressure of 1.5 atm until the piston has moved outwards through 15 cm. Assume that carbon dioxide may be considered a perfect gas with CVm = 28.8 J/K mol. Calculate: q w DeltaU DeltaZ DeltaS (Design two reversible paths to calculate deltaS. ft can be calculated from T1 and deltaT. Vt can be calculated from Vi and deltaV, where dletaV is the volume change resulting from piston displacement.)

Explanation / Answer

net force = difference in pressure*are of cross-section of cylinder = (9-1.5)*105*10-2 = 7500 N

Thus, work done = Force*distance travelled = 7500*0.15 = 1125 J = 1.125 kJ

In an adiabatic system, q = 0

Thus, work done = change in internal energy = 1.125 kJ

Now, change in internal energy = n*Cv*dT

or, 1125 = 1.5*28.8*dT

or, dT = 26.042

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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