Question

99% of a first order reaction, was completed in 32 minute. When will 99.9% of the reaction complete?

• A. 50 minute
• B. 46 minute
• C. 49 minute
• D. 48 minute

Answer 1

Answer: (D)

48 minute

$k=\frac{2.303}{t}log\frac{100}{100-x}$

Substituting the values,

$k=\frac{2.303}{32}log\frac{100}{1}$

$k=0.144{min}^{-1}$

$t=\frac{2.303}{0.144}log\frac{100}{0.1}$

$t=48min$