Question

A heat engine carries one mole of an ideal mono-atomic gas around the cycle as shown in the figure, the amount of heat added in the process AB and heat removed in the process CA are :

• A. qAB = 450 R and qCA = –450 R
• B. qAB = 450 R and qCA = –225 R
• C. qAB = 450 R and qCA = –375 R
• D. qAB = 375 R and qCA = –450 R

Answer 1

Answer: (C)

qAB = 450 R and qCA = –375 R

Answer 2

(3) At constant volume $\Delta$U = qv = nCvm $\Delta$T = $\frac{3}{2}$R × 300 = 450 R

at constant pressure $\Delta$H = qp = nCp,m $\Delta$T = $\frac{5}{2}$R (–150) = –375 R