Verified Solution • 2025–26 Session moderate

QJEEM21Chaa61: JEE Main 2021 Chemistry - Class 11 JEEM21Chaa61 Solution: For the reaction A (g) B (g) the value of the equilibrium…

For the reaction A(g) →\to B(g) the value of the equilibrium constant at 300 K and 1 atm is equal to 100.0. The value of Δ\Delta rG for the reaction at 300 K and 1 atm in J mol-1 is – xR, where x is _______. (Rounded off to the nearest integer)
[R = 8.31 J mol–1K-1 and ln 10 = 2.3)

Step-by-Step Verified Solution

For a reaction, A(g) →\to B(g)

Given, Kp (equilibrium constant) = 100

Temperature = 300 K

Pressure = 1 atm

Formula used, Δ\Delta G ∘^\circ = −- RT ln Kp .... (i)

Here, Δ\Delta G ∘^\circ = standard Gibb's free energy

R = gas constant = 8.31 J mol −- 1 K −- 1

Put value in Eq. (i), we get

Δ\Delta G ∘^\circ = −- R (300) ln 100

Δ\Delta G ∘^\circ = −- R (300) (2) ln (10)

∵\because ln (10) = 2.3

Δ\Delta G ∘^\circ = −- R(300) (2) (2.3)

Δ\Delta G ∘^\circ = −- 1380 R

Hence, Δ\Delta G ∘^\circ = −- xR

∴\therefore x = 1380

Related Learning Resources & Exam Preparation