Question

$99\%$ at a first order reaction was completed in $32$ min. When will $99.9\%$ of the reaction complete?

• A. 48 min
• B. 46 min
• C. 50 min
• D. 45 min

Answer 1

Answer: (A)

$k\times 32=ln\left(\frac{100}{1}\right).....\left(i\right)$
$k_2\times t=ln\left(\frac{100}{0.1}\right)...\left(ii\right)$
$eq\left(ii\right)\left(i\right)$
$\frac{t}{32}=\frac{3ln10}{2ln10}$
$t=48min$