Question

Mixing a liter of Nitrogen (N2) at 20oC having a pressure of 1 bar with 2liters of helium (He) at 30oC also at 1 bar pressure (i.e. at pressure
atmospheric).  The mixture is supposed to be perfect and is done in a 5 L container.

A) The vessel is in thermal contact with a heat source of320 K temperature, what is the pressure P1 inside the vessel when it reaches thethermal equilibrium?.

B) The mixture is then subjected to the following reversible cycle:Isothermal transformation of P1a P2 = 2 bars,isobar transformation reaching volume at 5 L, Isometric transformation just to the initial state.

C) Calculate the volume V2 at the end of the first transformation and represent the cycle in a Clapeyron diagram.

D) Calculate the work exchanged in each transformation and the total work of the cycle.
Is the sign of W (work) predictable?.

E) Compare work W with work W´ that the gas would have exchanged with the outside if the first transformation to reach the pressure of 2 bars had been reversible adiabatic.

Answer 1

use concepts of thermodynamics, first law, work done, ideal gases.