The 1,2-adduct and 1,4-adduct of HBr with buta-1,3-diene equilibrate at 313 K. For 1,2-adduct -> 1,4-adduct, Delta G deg = -4.00 kJ mol^-1 (R = 8.314 J mol^-1 K^-1). The percentage of the 1,4-adduct at equilibrium is closest to

JEE Advanced levelSingle correct optionDifficulty 3 of 3g3204

The 1,2-adduct and 1,4-adduct of HBr with buta-1,3-diene equilibrate at 313 K. For $1,2-adduct \to 1,4-adduct$ , $Δ G^{\circ} = - 4.00 kJ mo l^{- 1}$ ( $R = 8.314 J mo l^{- 1} K^{- 1}$ ). The percentage of the 1,4-adduct at equilibrium is closest to

K = exp (4000/ (8.314 \times 313)) = 4.65

. Percentage of 1,4-adduct

= 100 K / (1 + K) = 82.3%

, about 82%. The value 18% is the 1,2-adduct.