Question
After how many seconds will the concentration of the reactants in a first order reaction be halved, if the decay constant is ${\rm{1}}{\rm{.155}} \times {\rm{1}}{{\rm{0}}^{{\rm{ - 3}}}}\,{\sec ^{ - 1}}$ ........... $\sec$
✓
Answer
$t = \frac{{2.303}}{k}\log \frac{a}{{a - x}}$
$t = \frac{{2.303}}{{1.155 \times {{10}^{ - 3}}}}\log \frac{{100}}{{100 - 50}} = 600\,\sec $
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