For the process $\mathrm{H}_{2}\mathrm{O}(l)(1 \mathrm{bar}, 373 \mathrm{~K}) \rightarrow \mathrm{H}_{2}\mathrm{O}(g)(1$ bar, $373 \mathrm{~K})$, the correct set of thermodynamic parameters is

(A) $\Delta \mathrm{G}=0, \Delta \mathrm{~S}=+\mathrm{ve}$

(B) $\Delta \mathrm{G}=0, \Delta \mathrm{~S}=-\mathrm{ve}$

(C) $\Delta \mathrm{G}=+\mathrm{ve}, \Delta \mathrm{~S}=0$

(D) $\Delta \mathrm{G}=-\mathrm{ve}, \Delta \mathrm{~S}=+\mathrm{ve}$

JEE Advanced · 2007 · 08 Apr 2007 · Paper 2 · Chemical Thermodynamics

For the process

H_{2} O (l) (1 bar, 373 K) \to H_{2} O (g) (1

bar,

373 K)

, the correct set of thermodynamic parameters is

(A) $Δ G = 0, Δ S = + ve$ ✓ Correct
(B) $Δ G = 0, Δ S = - ve$
(C) $Δ G = + ve, Δ S = 0$
(D) $Δ G = - ve, Δ S = + ve$

Answer: (A)

Solution

At 373 K (100°C) and 1 bar pressure, liquid water and water vapor are in equilibrium. For a system at equilibrium,

Δ G = 0

. Since the process involves conversion of liquid to gas, the disorder (entropy) increases, so

Δ S

is positive. Therefore,

Δ G = 0

and

Δ S = + ve

JEE Advanced · 2007 · 08 Apr 2007 · Paper 2 · Single correct option

Practise more: all JEE Advanced PYQs on Chemical Thermodynamics →

More JEE Advanced questions on Chemical Thermodynamics

An ideal gas (0.5 mol), initially at 2 bar pressure, is compressed at a constant temperature of 600 K in two steps : first against a constant external pressure of P bar $(2 < P < 8)$ , and then against constant external pressure of 8 bar. At each step, the compression is st …
JEE Advanced 2026View solution →
List-I contains various physical/chemical processes, and List-II contains combinations of changes in enthalpy $(Δ H)$ and entropy $(Δ S)$ . Match each entry in List-I to appropriate entry in List-II, and choose the correct option.

| List-I | | List …
JEE Advanced 2026View solution →
Considering ideal gas behavior, the expansion work done (in kJ) when 144 g of water is electrolyzed completely under constant pressure at 300 K is ____.

Use: Universal gas constant $(R) = 8.3 J K^{- 1} mol^{- 1}$ ; Atomic mass (in amu): …
JEE Advanced 2025View solution →
Consider the following volume-temperature (V - T) diagram for the expansion of 5 moles of an ideal monoatomic gas.

(see diagram)

Considering only P-V work is involved, the total change in enthalpy (in Joule) for the transformation of state in the sequence …
JEE Advanced 2024View solution →
The entropy versus temperature plot for phases $α$ and $β$ at 1 bar pressure is given.
$S_{T}$ and $S_{0}$ are entropies of the phases at temperatures T and 0 K, respectively.

(see diagram)

The transition temperature for $α$ to …
JEE Advanced 2023View solution →
The entropy versus temperature plot for phases $α$ and $β$ at 1 bar pressure is given.
$S_{T}$ and $S_{0}$ are entropies of the phases at temperatures T and 0 K, respectively.

(see diagram)

The transition temperature for $α$ to …
JEE Advanced 2023View solution →