JEE Main 28 Jan 2026 Shift 2 Paper Solved Paper

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 the same temperature; then rate constant for the second reaction at 300 K is ____ ×10−1 hour ‌−1 (nearest integer).