For the first-order reaction t_99% = x × t_90%. The value of 'x' will be — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

For a first-order reaction, t = 2.303/K log(a/(a-x)). For 99% completion: t_99% = 2.303/K log(100/1) = 2.303/K × 2. For 90% completion: t_90% = 2.303/K log(100/10) = 2.303/K × 1. Therefore, t_99% = 2 × t_90%, so x = 2.