Question

Half-life period of a first order reaction is 10 min. what percentage of the reaction will be completed in 100 min?

• A. 25%
• B. 50%
• C. $99.9\%$
• D. 75%

Answer 1

Answer: (C)

$99.9\%$

Answer 2

$\frac{0.693}{t_{1/2}} = \frac{2.303}{t}\log\frac{a}{a - x}$

$\frac{0.693}{10} = \frac{2.303}{t}\log\frac{100}{100 - x} \Rightarrow x = 99.9$