1. Tardigrade
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  3. Chemistry
  4. The rate of a first order reaction is 0.04 mol l-1 s-1 at 10 seconds and 0.03 mol l-1 s-1 at 20 seconds after initiation of the reaction. The half-life period of the reaction is :

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Q. The rate of a first order reaction is $0.04 mol \, l^{-1} \, s^{-1}$ at 10 seconds and $0.03 \, mol \, l^{-1} \, s^{-1}$ at 20 seconds after initiation of the reaction. The half-life period of the reaction is :

NEETNEET 2016Chemical Kinetics

Solution:

$K = \frac{2.303}{10} \log \frac{0.04}{0.03} $
$ K = \frac{2.303}{10} \log \frac{4}{3}$
$ K = \frac{2.303 \times0.123}{10}$
$ K = 0.0285 t_{1/2} = \frac{0.693}{K} $
$ t_{1/2} = \frac{0.693}{0.0285} = 24.1s.$