Question

For a reaction: $X\left(g\right)\to Y\left(g\right)+Z\left(g\right)$
The half-life period is 10 min. In what period of time would be concentration of X be reduced to 10% of original concentration?

• A. 20 min.
• B. 33 min.
• C. 15 min.
• D. 25 min.

Answer 1

The correct option is B 33 min.

$k=\frac{0.693}{t_{\frac{1}{2}}}=\frac{0.693}{10}$
$t=\frac{2.303}{k}log\frac{a}{a-x}=\frac{2.303\times 10}{0.693}\times log\frac{100}{10}=33min.$