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A first order reaction has a rate constant k = 5.5 x 10^-14 s^-1. What is its half-life?
A1.26 x 10^13 s
B3.81 x 10^13 s
C1.26 x 10^14 s
D7.93 x 10^-14 s
Answer & Solution
Correct answer: A. 1.26 x 10^13 s
1. For first order, $t_{1/2} = \dfrac{0.693}{k}$.
2. $= \dfrac{0.693}{5.5\times10^{-14}}$.
3. $= 1.26\times10^{13}\ \text{s}$.
_Source: NCERT Class 12 Chemistry Ch 3 "Chemical Kinetics", p.16_
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