A first order reaction is found to have a rate constant, $k = 5.5 × 10^{-14} s^{-1}$. The half life of the reaction will be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → $1.26 × 10^{13} s$
For a first-order reaction, the half-life is given by:
$t_{1/2} = \frac{0.693}{k}$
Given:
$k = 5.5 \times 10^{-14}\ \text{s}^{-1}$
$t_{1/2} = \frac{0.693}{5.5 \times 10^{-14}} = 0.126 \times 10^{14} = 1.26 \times 10^{13}\ \text{s}$