A first order reaction `A rarr B` requires activation energy of `70 kJ mol^(-1)`. When a `20%` solution of `A` was kept at `25^(@)C` for `20 min`, `25%` decomposition took place. What will be the percentage decomposition in the same time in a `30%` solution maintained at `40^(@)C` ? (Assume that activation energy remains constant in this range of temperature)

Explanation

First calculate `k_25`, then `k_49` . Again find out per cent decomposition at `40^@C`
67.17%