For a gaseous equilibrium, K = 0.10 at 300 K and K = 0.80 at 400 K. Using R = 8.314 J mol^-1 K^-1 and assuming Delta H deg constant, Delta H deg in kJ/mol is about

JEE Advanced levelSingle correct optionDifficulty 3 of 3ce212

For a gaseous equilibrium, $K = 0.10$ at $300 K$ and $K = 0.80$ at $400 K$ . Using $R = 8.314 J mo l^{- 1} K^{- 1}$ and assuming $Δ H^{\circ}$ constant, $Δ H^{\circ}$ in kJ/mol is about

ln (K_{2} / K_{1}) = ln 8 = 2.0794

and

1/300 - 1/400 = 8.333 \times 1 0^{- 4} K^{- 1}

Δ H = 8.314 \times 2.0794/ (8.333 \times 1 0^{- 4}) = 20.75

kJ/mol (positive, as

K

rises with

T