The values of pressure equilibrium constant recorded at different temperatures for the following equilibrium reaction have been given below: $\mathrm{A}(\mathrm{g}) \rightleftharpoons \mathrm{B}(\mathrm{g})+\mathrm{C}(\mathrm{g})$ | $\frac{1}{\mathrm{~T}}(\mathrm{~K}^{-1})$ | $\log_{10} \mathrm{~K}_{\mathrm{p}}$ | |---|---| | 0.05 | 3.5 | | 0.06 | 2.5 | | 0.07 | 1.5 | The magnitude of $\frac{\Delta \mathrm{H}^{\circ}}{\mathrm{R}}$ calculated from the above data is ____.(Nearest integer)

JEE Main · 2026 · 05 Apr 2026 · Shift 1 · Chemical Thermodynamics

The values of pressure equilibrium constant recorded at different temperatures for the following equilibrium reaction have been given below:

A (g) ⇌ B (g) + C (g)

The magnitude of

\frac{Δ H ^{\circ}}{R}

calculated from the above data is ____.(Nearest integer)

Answer: 230

The temperature dependence of the equilibrium constant obeys

lo g K_{p} = - \frac{Δ H ^{\circ}}{2.303 R} \cdot \frac{1}{T} + constant

, so a graph of

lo g K_{p}

against

1/ T

is a straight line of slope

- \frac{Δ H ^{\circ}}{2.303 R}

. From the data the slope is

\frac{1.5 - 3.5}{0.07 - 0.05} = - 100 K

. Equating this to

- \frac{Δ H ^{\circ}}{2.303 R}

gives

\frac{Δ H ^{\circ}}{R} = 2.303 \times 100 = 230.3 K

, whose magnitude to the nearest integer is

230

JEE Main · 2026 · 05 Apr 2026 · Shift 1 · Integer answer