One mole of an ideal nonlinear triatomic gas expands under PV²=constant. If its process molar heat capacity is NR, find N.
Physics · Mixed Chapter
JEE Main Practice

Question

One mole of an ideal nonlinear triatomic gas expands under PV²=constant. If its process molar heat capacity is NR, find N.

G1 Physics · Accepted Answer

Step 1: An ideal nonlinear triatomic gas has f=6, so Cᵥ=3R. Step 2: PV²=constant implies PV²=K. Since PV=RT, RT=K/V ⇒T∝1/V. Step 3: Therefore dV/V=−dT/T and work PdV=RT(dV/V)=−R dT. Step 4: δQ=Cᵥ dT+PdV=(3R−R)dT=2R dT. Hence N=2.