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 the concentration of X be reduced to 10% of the original concentration ?

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

Answer 1

The correct option is B 33 min

$\frac{t_{10\%\left(left\right)}}{t_{1/2}}=\frac{log\left(\frac{100}{10}\right)}{0.3}$

$t_{10\%}\left(left\right)=\frac{t_{1/2}\times 1}{0.3}$

$=\frac{10min}{0.3}=33min$