The standard enthalpy and standard entropy of decomposition of $\mathrm{N}_{2} \mathrm{O}_{4}$ to $\mathrm{NO}_{2}$ are $55.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and $175.0 \mathrm{~J} / \mathrm{K} / \mathrm{mol}$ respectively. The standard free energy change for this reaction at $25^{\circ} \mathrm{C}$ in $\mathrm{J} \mathrm{mol}^{-1}$ is ______ (Nearest integer)

JEE Main · 2025 · 23 Jan 2025 · Shift 1 · Chemical Thermodynamics

The standard enthalpy and standard entropy of decomposition of

N_{2} O_{4}

NO_{2}

are

55.0 kJ mol^{- 1}

and

175.0 J / K / mol

respectively. The standard free energy change for this reaction at

2 5^{\circ} C

J mol^{- 1}

is
______ (Nearest integer)

Answer: 2850

The Gibbs free energy change of a reaction is obtained from

Δ G^{\circ} = Δ H^{\circ} - T Δ S^{\circ}

.

With

Δ H^{\circ} = 55.0 kJ mo l^{- 1} = 55000 J mo l^{- 1}

Δ S^{\circ} = 175.0 J K^{- 1} mo l^{- 1}

and

T = 298 K

Δ G^{\circ} = 55000 - (298) (175) = 55000 - 52150 = 2850 J mo l^{- 1}

JEE Main · 2025 · 23 Jan 2025 · Shift 1 · Integer answer