JEE Main · 2019 · 12 Jan 2019 · Shift 1 · Chemical Thermodynamics

WhatsApp Email

For a disatomic ideal gas in a closed system, which of the following plots does not correctly describe the relation between various thermodynamic quantities?

(A)(see structure)
(B)(see structure)
(C)(see structure)
✓ Correct
(D)(see structure)

Answer: (C)

Solution

For an ideal gas the molar heat capacity at constant pressure,

C_{P}

, is set only by the temperature and the molecule's degrees of freedom; it does not change when the pressure is varied at fixed temperature. A graph that shows

C_{P}

rising or falling with pressure therefore misrepresents the behaviour of an ideal gas, so that is the plot which does not correctly describe the relationship.

JEE Main · 2019 · 12 Jan 2019 · Shift 1 · Single correct option

Practise more: all JEE Main PYQs on Chemical Thermodynamics →

More JEE Main questions on Chemical Thermodynamics

Which of the following graphs between pressure 'P' versus volume 'V' represent the maximum work done?
JEE Main 2026View solution →
For the reaction, $N_{2} O_{4} ⇌ 2 NO_{2}$ , graph is plotted as shown below. Identify correct statements.

A. Standard free energy change for the reaction is $- 5.40 kJ mol^{- 1}$ .
B. As $Δ G^{⊖}$ in graph i …
JEE Main 2026View solution →
Use the following data:
Substance $\frac{Δ _{f} H ^{⊖} ( 500 K )}{kJ mol ^{- 1}}$ $\frac{S ^{⊖} ( 500 K )}{J K ^{- 1} mol ^{- 1}}$
| …
JEE Main 2026View solution →
Dissociation of a gas $A_{2}$ takes place according to the following chemical reactions. At equilibrium, the total pressure is 1 bar at 300 K.
$A_{2} (g) ⇌ 2 A (g)$
The standard Gibbs energy of formation of the involv …
JEE Main 2026View solution →
Consider the following data:
$Δ_{f} H^{Θ}$ (methane, g) $= - X kJ mol^{- 1}$
Enthalpy of sublimation of graphite $= Y kJ mol^{- 1}$
Dissociation enthalpy of …
JEE Main 2026View solution →
If the enthalpy of sublimation of Li is $155 kJ mol^{- 1}$ , enthalpy of dissociation of $F_{2}$ is $150 kJ mol^{- 1}$ , ionization enthalpy of Li is $520 kJ mol^{- 1}$ , electron gain enthalpy of F is $- 313 kJ mol^{- 1}$ , standard enthalpy o …
JEE Main 2026View solution →