Question

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

• A. $50\min$
• B. $46\min$
• C. $49\min$
• D. $48\min$

Answer 1

Answer: (D)

$k=2.30332\log \frac{a}{a-0.99a}=0.1439{\min }^{-1}$
$t=\frac{2.303}{0.1439}\log \frac{a}{a-0.999a}=48\min$