Answer to Question #211685 in Molecular Physics | Thermodynamics for Pontsho Maphosa

Question

4. A system consisting of 0.32 mol of a diatomic ideal gas undergoes a cycle starting at 

point A (2 atm, 1L). The following process is carried through a cycle:

(a) The gas is heated at constant pressure until its volume is 2.5 L at point B.

(b) The gas is cooled at constant volume until the pressure is 1 atm at point C.

(c) The gas is compressed at constant pressure until its volume is 1L at point D.

(d) The gas is heated until it goes back to initial point.

i. Show the processes on a diagram.

(4)

ii. Calculate the temperatures at point A and point B.

(6)

iii. Calculate the work done on each process.

Answer 1

$T_A=\frac{p_AV_A}{\nu R}=76.2~K,$

$T_B=T_A\frac{V_B}{V_A}=190.5~K,$

$A_{AB}=p_AV_{AB}=304~J,$

$A_{BC}=0~J,$

$A_{CD}=-A_{AB}=-304~J,$

$A_{DA}=0~J.$