Quantrex Academy · Free JEE Advanced PYQ solutions
JEE Advanced Chemistry Thermodynamics (C) 2021 JEE Advanced 2021 (Paper 1)

JEE Advanced Chemistry Question (2021) — Solution

Question

An ideal gas undergoes a reversible isothermal expansion from state I to state II followed by a reversible adiabatic expansion from state II  to state III .  The correct plot  s representing the changes from state  I to state III  is(are) ( p : pressure, V : volume, T : temperature, H : enthalpy, S : entropy)

Options

  1. A.
  2. B.
  3. C.
  4. D.

Answer

D.

Step-by-step solution

Reversible isothermal expansion from  I → II  during this process T =  constant ΔH = ΔU = 0 H =  constant. ΔS ≠ 0  Entropy will increase  PV =  constant. and during adiabatic reversible expansion. q = 0 ΔU = w = − ve so  T  will decrease ΔH = nc p ΔT = - ve H  will decrease ΔS = 0  (isoentropic process) S = constant. and  pv r =  constant. Keeping in mind correct graph are 1,2 and 4.  

Practice more on Quantrex App →

Related: Chemistry — Thermodynamics (C) · All PYQ Banks