Chemistry - Chemical Kinetics Question with Solution | TestHub

Given $t_{1/2}=10$ minutes and total time $t=30$ minutes.

Number of half-lives $n=\frac{t}{t_{1/2}}=\frac{30}{10}=3$

For a first order reaction, the amount of reactant remaining after $n$ half-lives is given by:

$N=N_0{\left(\frac{1}{2}\right)}^n$

Substituting the given values:

$N=1\times {\left(\frac{1}{2}\right)}^3$

$N=\frac{1}{8}=0.125\text{g}$

Answer: $0.125\text{g}$