JEE Main202628 January 2026Evening ShiftChemistryChemical KineticsActual
A B (first reaction) C D (second reaction) Consider the above two first-order reactions. The rate constant for first reaction at 500 K is double of the same at 300 K. At 500 ~K , 50 % of the reaction becomes complete in 2 hour. The activation energy of the second reaction is half of that of first reaction. If the rate constant at 500 K of the second reaction becomes double of the rate constant of first reaction at th
Correct answer
0
Step-by-step solution
For A K₁ B (2) = E_ a₁ R [ 1 300 - 1 500 ] E_ a₁ = 2 R 1500 2 E_ a₂ = E_ a₁ 2 = 2 R 1500 4 (K₁)_ at 500 K = 2 2 (K₂)_ at 500 K = 2 Now for C K₂ D [ (K₂)_ at 500K (K₂)_ at 300K ] = ( 2 R 1500 4 ) 1 R [ 1 300 - 1 500 ] (K₂)_ at 300 K = 2 2 = 0.49 (K₂)_ at 300 K = 4.9 10⁻¹ . So, answer is 5.